Free CDL General Knowledge Practice Test 2019

QUESTION NO: 1

When you check the engine compartment during the pre-trip vehicle inspection, __________
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A. make sure that the parking brake is on, and/or the wheels are chocked.
B. look at the gauges.
C. check the steering wheel and clutch for looseness, sticking, damage, or improper setting.
D. all of the above

Answer: A

Explanation:

When you check the engine compartment during step two of the pre-trip vehicle inspection, make sure that the parking brakes are on and/or the wheels are chocked. Check the engine oil level, coolant level in radiator and condition of hoses, power steering fluid level and hose condition (if so equipped), windshield washer fluid level, battery fluid level, connections, and tie downs (the battery may be located elsewhere), and automatic transmission fluid level (which may require the engine to be running).
Check the belts for tightness and excessive wear (alternator, water pump, and air compressor). Learn how much “give” the belts should have when adjusted correctly, and check each one. Check for leaks in the engine compartment (fuel, coolant, oil, power steering fluid, hydraulic fluid, and battery fluid) and look for cracked, worn electrical wiring insulation. Lower and secure hood, cab, or engine compartment door.

QUESTION NO: 2

The combined strength of all cargo tiedowns must be enough to lift __________ times the weight of the piece of cargo tied down.
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A. one and one-half
B. two
C. two and one-half
D. none of the above

Answer: A

Explanation:

You must understand basic cargo safety rules to get a CDL. If you load cargo wrong or do not secure it, it can be a danger to others and yourself. On flatbed trailers or trailers without sides, cargo must be secured to keep it from shifting or falling off. In closed vans, tiedowns can also be important to prevent cargo shifting that may affect the handling of the vehicle. Tiedowns must be of the proper type and proper strength. The combined strength of all cargo tiedowns must be strong enough to lift one and one-half times the weight of the piece of cargo tied down. Proper tiedown equipment must be used, including ropes, straps, chains, and tensioning devices (winches, ratchets, clinching components). Tiedowns must be attached to the vehicle correctly (hooks, bolts, rails, rings). Cargo should have at least one tiedown for each ten feet of cargo. Make sure you have enough tiedowns to meet this need. No matter how small the cargo, it should have at least two tiedowns. There are special requirements for securing various heavy pieces of metal. Find out what they are if you are to carry such loads.

QUESTION NO: 3

Distracted driving can occur when __________
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A. you take your eyes off the road.
B. you take your hands off the wheel.
C. mental activities take your attention away from driving.
D. any of the above

Answer: D

Explanation:

Whenever you are driving a vehicle and your attention is not on the road, you’re putting yourself, your passengers, other vehicles, and pedestrians in danger. Distracted driving can result when you perform any activity that may shift your full attention from the driving task. Taking your eyes off the road or hands off the steering wheel presents obvious driving risks. Mental activities that take your mind away from driving are just as dangerous. Your eyes can gaze at objects in the driving scene but fail to see them because your attention is distracted elsewhere.

QUESTION NO: 4

Driving too fast reduces the time you have to react to an emergency and increases your __________
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A. impact force.
B. braking distance.
C. both A and B
D. none of the above

Answer: C

Explanation:

Whenever you double your speed, it takes about four times as much distance to stop and your vehicle will have four times the destructive power if it crashes. High speeds increase stopping distances greatly. By slowing down a little, you can gain a lot in reduced braking distance.

QUESTION NO: 5

In the winter, pay extra attention to these items when conducting a pre-trip inspection: __________
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A. tires, engine oil, engine belts, and hoses.
B. tires, coolant level and antifreeze amount, tire chains, and lights and reflectors.
C. tires, engine oil, windows and mirrors, and engine belts.
D. engine oil, engine coolant, engine belts, and hoses.

Answer: B

Explanation:

Make sure your vehicle is ready before driving in winter weather. Be sure you have enough tread on your tires. The drive tires must provide traction to push the rig over wet pavement and through snow. The steering tires must have traction to steer the vehicle. Enough tread is especially important in winter conditions. You must have at least 4/32 inch tread depth in every major groove on front tires and at least 2/32 inch on other tires. More would be better, Use a gauge to determine if you have enough tread for safe driving. Make sure the cooling system is full and that there is enough anti-freeze in the system to protect against freezing. This can be checked with a special coolant tester.
You may find yourself in conditions where you can’t drive without chains, even to get to a place of safety. Carry the right number of chains and extra cross links. Make sure they will fit your drive tires. Check the chains for broken hooks, worn or broken cross links, and bent or broken side chains. Learn how to put the hooks on before you need to do it in snow and ice. Make sure the lights and reflectors are clean. Lights and reflectors are especially important during bad weather. Check from time to time during bad weather to make sure that they are clean and working properly.

QUESTION NO: 6

With a BAC of __________, the effect on the body is noticeable relaxation, and the effect on the driving condition is to make the driver less alert and less self-focused; also, coordination impairment begins.
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A. .05
B. .10
C. .15
D. .20

Answer: A

Explanation:

Blood Alcohol Content is the amount of alcohol in your blood recorded in milligrams of alcohol per 100 millimeters of blood or milligrams. Your BAC depends on the amount of blood (which increases with weight) and the amount of alcohol you consume over time (how fast you drink). The faster you drink, the higher your BAC, as the liver can only handle about one drink per hour-the rest builds up in your blood. With a BAC of .05, the effect on the body is noticeable relaxation, and the effect on the driving condition is to make the driver less alert and less self-focused. Coordination impairment begins.

QUESTION NO: 7

__________ are Class 8 (Corrosives) hazardous materials.
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A. Propane, oxygen, and helium
B. Dynamite, fireworks, and ammunition
C. Hydrochloric acid and battery acid
D. Gasoline fuel and acetone

Answer: C

Explanation:

Hazardous materials are products that pose a risk to health, safety, and property during transportation. Hydrochloric acid and battery acid are Class 8 (Corrosives) hazardous materials.

QUESTION NO: 8

ABS __________
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A. shortens stopping distance.
B. won’t compensate for bad brakes or poor brake maintenance.
C. changes the way you normally brake.
D. all of the above

Answer: B

Explanation:

ABS won’t allow you to drive faster, follow more closely, or drive less carefully. It won’t prevent power or turning skids-ABS should prevent brake-induced skids or jackknifes, but not those caused by spinning the drive wheels or going too fast in a turn. ABS won’t necessarily shorten stopping distance. It will help maintain vehicle control, but not always shorten stopping distance. ABS won’t increase or decrease ultimate stopping power-ABS is an “add-on” to your normal brakes, not a replacement for them. ABS won’t change the way you normally brake. Under normal brake conditions, your vehicle will stop as it always stopped. ABS only comes into play when a wheel would normally have locked up because of over braking. ABS won’t compensate for bad brakes or poor brake maintenance. Remember: The best vehicle safely feature is still a safe driver. Drive so you never need to use your ABS. If you need it, ABS could help to prevent a serious crash.

QUESTION NO: 9

Before starting down a hill, __________
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A. accelerate and shift up.
B. accelerate and shift down.
C. slow down and shift up.
D. slow down and shift down.

Answer: D

Explanation:

Special conditions where you should downshift are before starting down a hill and before entering a curve. Before entering a curve, slow down to a safe speed. Before starting down a hill, slow down and shift down to a speed that you can control without using the brakes hard. Otherwise the brakes can overheat and lose their braking power. Downshift before starting down the hill. Make sure you are in a low enough gear, usually lower than the gear required to climb the same hill.

QUESTION NO: 10
Containment rules for hazardous materials __________
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A. are shipping papers and package labels that warn dockworkers and drivers of associated risks.
B. protect drivers and others from contact with products that could injure or kill them.
C. are signs put on the outside of a vehicle which identify the hazard class of the cargo.
D. explain how to get a hazardous materials endorsement on your commercial driver license.

Answer: B

Explanation:

You must follow the many rules about transporting hazardous materials. The intent of the rules is to contain the product, communicate the risk, and ensure safe drivers and equipment. Many hazardous products can injure or kill on contact. To protect drivers and others from contact, the rules tell shippers how to package safely. Similar rules tell drivers how to load, transport, and unload bulk tanks. These are containment rules. The shipper uses a shipping paper and diamond shaped hazard labels to warn dockworkers and drivers of the risk. After an accident or hazardous material spill or leak, you may be injured and unable to communicate the hazards of the materials you are transporting. Firefighters and police can prevent or reduce the amount of damage or injury at the scene if they know what hazardous materials are being carried. Your life, and the lives of others, may depend on quickly locating the hazardous materials shipping papers. For that reason, you must tab shipping papers related to hazardous materials or keep them on top of other shipping papers. You must also keep shipping papers in a pouch on the driver’s door, or in clear view within reach while driving, or on the driver’s seat when out of the vehicle.

QUESTION NO: 11
A safe way to approach the issue of overhead clearance is __________
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A. to assume that the heights posted at bridges and overpasses are correct.
B. realize that re-paving or packed snow may have increased the amount of clearance since warning signs were posted.
C. to get out of your vehicle and check for overhanging objects, such as tree branches and electric wires, before backing.
D. all of the above

Answer: C

Explanation:

Hitting overhead objects is a danger. Make sure you always have overhead clearance. Before you back into an area, get out and check for overhanging objects, such as trees, branches, or electric wires. It’s easy to miss seeing them while you are backing. Check for other hazards at the same time. Don’t assume that the heights posted at bridges and overpasses are correct. Repaving or packed snow may have reduced the clearances since the heights were posted. If you doubt that you have safe space to pass under an object, go slowly. If you aren’t sure you can make it, take another route. Warnings are often posted on low bridges or underpasses, but sometimes they are not.

QUESTION NO: 12
When using double clutching to shift up, you should push in the clutch and shift to the higher gear immediately after you __________
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A. release the accelerator, push in the clutch, and shift to neutral at the same time.
B. release the clutch.
C. let the engine and gears slow down to the rpm required for the next gear.
D. none of the above

Answer: C

Explanation:

Correct shifting of gears is important. If you can’t get your vehicle into the right gear while driving, you will have less control. Most heavy vehicles with manual transmissions require double clutching to change gears. When using double clutching to shift up, first release the accelerator, push in the clutch, and shift to neutral at the same time. Release the clutch. Let the engine and gears slow down to the rpm required for the next gear (this takes practice). Push in the clutch and shift to the higher gear at the same time. Release the clutch and press the accelerator at the same time.

QUESTION NO: 13
If you do not load and secure cargo yourself, you are only responsible for __________
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A. inspecting the cargo.
B. recognizing overloads and poorly balanced weight.
C. knowing your cargo is properly secured.
D. all of the above

Answer: D

Explanation:

You must understand basic cargo safety rules to get a CDL. If you load cargo wrong or do not secure it, it can be a danger to others and yourself. Loose cargo that falls off a vehicle can cause traffic problems and others could be hurt or killed. Loose cargo could hurt or kill you during a quick stop or crash. Your vehicle could be damaged by an overload. Steering could be affected by how a vehicle is loaded, making it more difficult to control the vehicle. Whether or not you load and secure the cargo yourself, you are responsible for: -Inspecting your cargo. -Recognizing overloads and poorly balanced weight. -Knowing your cargo is properly secured and does not obscure your view ahead or to the sides. -Knowing your cargo does not restrict your access to emergency equipment. If you intend to carry hazardous material that requires placards on your vehicle, you will also need to have a hazardous materials endorsement.

QUESTION NO: 14
To correct a skid caused by acceleration if the road is very slippery, __________
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A. take your foot off the accelerator and push in the clutch.
B. take your foot off the accelerator and release the clutch.
C. gently apply the brake and push in the clutch.
D. gently apply the brake and release the clutch.

Answer: A

Explanation:

By far the most common skid is one in which the rear wheels lose traction through excessive braking or acceleration. Skids caused by acceleration usually happen on ice or snow. Taking your foot off the accelerator can easily stop them. (If it is very slippery, push the clutch in. Otherwise, the engine can keep the wheels from rolling freely and regaining traction.) Rear wheel braking skids occur when the rear drive wheels lock. Because locked wheels have less traction than rolling wheels, the rear wheels usually slide sideways in an attempt to “catch up” with the front wheels. In a bus or straight truck, the vehicle will slide sideways in a “spin out.” With vehicles towing trailers, a drive-wheel skid can let the trailer push the towing vehicle sideways, causing a sudden jackknife.

QUESTION NO: 15
For fire prevention, __________, which means making a complete inspection of the electrical, fuel, and exhaust systems, tires, and cargo, and making sure the fire extinguisher is charged.
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A. make a pre-trip inspection
B. make an en route inspection
C. follow safe procedures
D. use monitoring

Answer: A

Explanation:

Truck fires can cause damage and injury. Learn the causes of fires and how to prevent them. Know what to do to extinguish fires. During your pre-trip inspection, make a complete check of the electrical, fuel, and exhaust systems, tires, and cargo. Be sure to check that the fire extinguisher is charged.

QUESTION NO: 16
__________ is the total weight of a powered unit plus trailer(s) plus the cargo.
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A. Gross Vehicle Weight
B. Gross Combination Weight
C. Gross Combination Vehicle Weight
D. none of the above

Answer: B

Explanation:

You must understand basic cargo safety rules to get a CDL. If you load cargo wrong or do not secure it, it can be a danger to others and yourself. You are responsible for not being overloaded. Gross Combination Weight is the total weight of a powered unit plus trailer(s) plus the cargo.

QUESTION NO: 17
__________ ice is a thin layer of ice that is clear enough that you can see the road underneath it.
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A. Melting
B. Vehicle
C. Black
D. none of the above

Answer: C

Explanation:

Sometimes it’s hard to know if the road is slippery. Black ice is a thin layer of ice that is clear enough that you can see the road underneath it. It makes the road look wet. Any time the temperature is below freezing and the road looks wet, watch out for black ice.

QUESTION NO: 18
An example of a key air suspension part is the __________
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A. steering gear box.
B. upper bellows support.
C. spindle.
D. none of the above

Answer: B

Explanation:

Examples of key air suspension parts include: frame reinforcement, height control valve, upper bellows support, shock absorber, spacer, bracket, eye bolt, control arm, clamp bolt, anchor plate, axle, U-bolt, axle seat, lower bellows support, and bellows.

QUESTION NO: 19
When turning to avoid an emergency, __________
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A. do not apply the brake while you are turning.
B. do not turn any more than needed to clear whatever is in your way.
C. be prepared to “countersteer,” that is, to turn the wheel back in the other direction, once you’ve passed whatever was in your path.
D. all of the above

Answer: D

Explanation:

Stopping is not always the safest thing to do in an emergency. When you don’t have enough room to stop, you may have to steer away from what’s ahead. Remember, you can almost always turn to miss an obstacle more quickly than you can stop. A quick turn can be made safely, if it’s done the right way. Here are some points that safe drivers use: -Do not apply the brake while you are turning. It’s very easy to lock your wheels while turning. If that happens, you may skid out of control. -Do not turn any more than needed to clear whatever is in your way.
The more sharply you turn, the greater the chances of a skid or rollover. -Be prepared to “countersteer,” that is, to turn the wheel back in the other direction, once you’ve passed whatever was in your path. Unless you are prepared to countersteer, you won’t be able to do it quickly enough. You should think of emergency steering and countersteering as two parts of one driving action.

QUESTION NO: 20
If your vehicle has retarder controls, they should be checked when you __________ during the pre-trip vehicle inspection.
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A. check the condition of controls
B. review the last inspection report
C. check emergency equipment
D. none of the above

Answer: A

Explanation:

Check the condition of controls during step three of the pre-trip vehicle inspection. Check all of the following for looseness, sticking, damage, or improper setting: steering wheel, clutch, accelerator (“gas pedal”), brake controls, including the foot brake, trailer brake (if the vehicle has one), parking brake, and retarder controls (if the vehicle has them), transmission controls, interaxle differential lock (if the vehicle has one), horn(s), windshield wiper and washer, and lights (headlights, dimmer switch, turn signal, four-way flashers, and parking, clearance, identification, and marker switch(es)).

QUESTION NO: 21
When you double your speed, it takes about __________ times as much distance to stop and your vehicle will have four times the destructive power if it crashes.
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A. two
B. three
C. four
D. five

Answer: C

Explanation:

Whenever you double your speed, it takes about four times as much distance to stop and your vehicle will have four times the destructive power if it crashes. High speeds increase stopping distances greatly. By slowing down a little, you can gain a lot in reduced braking distance.

QUESTION NO: 22
The light from dirty headlights may be reduced by up to __________
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A. 10%
B. 25%
C. 50%
D. 75%

Answer: C

Explanation:

You are at greater risk when you drive at night. The problems of night driving involve the driver (such as vision and fatigue), the roadway (examples are poor lighting and drunk drivers) and the vehicle (headlights, windshield, and mirrors). Night driving can be more dangerous if you have problems with your headlights.
Dirty headlights may give only half the light they should. This cuts down your ability to see, and makes it more difficult for others to see you. Make sure your lights are clean and working. Headlights can be out of adjustment. If they don’t point in the right direction, they won’t give you a good view and they can blind other drivers. Have a qualified person make sure they are adjusted properly.

QUESTION NO: 23
You must keep shipping papers related to hazardous materials __________
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A. in a pouch on the passenger’s door.
B. in clear view within reach while driving.
C. on the passenger’s seat when out of the vehicle.
D. any of the above

Answer: B

Explanation:

You must follow the many rules about transporting hazardous materials. The intent of the rules is to contain the product, communicate the risk, and ensure safe drivers and equipment. Many hazardous products can injure or kill on contact. To protect drivers and others from contact, the rules tell shippers how to package safely. Similar rules tell drivers how to load, transport, and unload bulk tanks. These are containment rules.
The shipper uses a shipping paper and diamond shaped hazard labels to warn dockworkers and drivers of the risk. After an accident or hazardous material spill or leak, you may be injured and unable to communicate the hazards of the materials you are transporting. Firefighters and police can prevent or reduce the amount of damage or injury at the scene if they know what hazardous materials are being carried. Your life, and the lives of others, may depend on quickly locating the hazardous materials shipping papers.
For that reason, you must tab shipping papers related to hazardous materials or keep them on top of other shipping papers. You must also keep shipping papers in a pouch on the driver’s door, or in clear view within reach while driving, or on the driver’s seat when out of the vehicle.

QUESTION NO: 24
The advance warning sign at a railroad-highway grade crossing tells you to __________
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A. slow down.
B. look and listen for the train.
C. be prepared to stop at the tracks if a train is coming.
D. all of the above

Answer: D

Explanation:

Advance warning signs are round, black-on-yellow warning signs placed ahead of a public railroad-highway crossing. The advance warning sign tells you to slow down, look and listen for the train, and be prepared to stop at the tracks if a train is coming.

QUESTION NO: 25
When a tire fails, you must __________
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A. hit the brakes quickly.
B. let go of the steering wheel.
C. check the tires even if the vehicle seems to be handling properly.
D. all of the above

Answer: c

Explanation:

When a tire fails, your vehicle is in danger. You must immediately: -Hold the Steering Wheel Firmly. If a front tire fails, it can twist the steering wheel out of your hand. The only way to prevent this is to keep a firm grip on the steering wheel with both hands at all times. -Stay Off the Brake. It’s natural to want to brake in an emergency. However, braking when a tire has failed could cause loss of control.
Unless you’re about to run into something, stay off the brake until the vehicle has slowed down. Then brake very gently, pull off the road, and stop. -Check the Tires. After you’ve come to a stop, get out and check all the tires. Do this even if the vehicle seems to be handling all right. If one of your dual tires goes, the only way you may know it is by getting out and looking at it.

QUESTION NO: 26
If you have to drive with a cold, you __________
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A. are better off suffering with the cold than from the effects of a cold medicine.
B. should take the lowest recommended dose of cold medicine and take frequent breaks.
C. should take cold medicine, keep the cab warm, and drink plenty of liquids.
D. are better off suffering the effects of a cold medicine than from the effects of the cold.

Answer: A

Explanation:

Driving a vehicle for long hours is tiring. Even the best of drivers will become less alert. However, there are things that good drivers do to help stay alert and safe. Avoid medication. Many medicines can make you sleepy. Those that do have a label warning against operating vehicles or machinery.
The most common medicine of this type is an ordinary cold pill. If you have to drive with a cold, you are better off suffering from the cold than from the effects of the medicine. Visit your doctor. Regular checkups literally can be lifesavers. Illnesses such as diabetes, heart disease, and skin and colon cancer can be detected easily and treated if found in time. You should consult your physician or a local sleep disorder center if you suffer from frequent daytime sleepiness, have difficulty sleeping at night, take frequent naps, fall asleep at strange times, snore loudly, gasp and choke in your sleep, and/or wake up feeling as though you have not had enough sleep.

QUESTION NO: 27
On slippery surfaces, __________
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A. it will take longer to stop.
B. it will be harder to turn.
C. you must drive slower to be able to stop in the same distance as on a dry road.
D. all of the above

Answer: D

Explanation:

It will take longer to stop and it will be harder to turn without skidding when the road is slippery. Wet roads can double stopping distance. You must drive slower to be able to stop in the same distance as on a dry road. Reduce speed by about one third (for example, slow from 55 to about 35 mph) on a wet road. On packed snow, reduce speed by half or more. If the surface is icy, reduce speed to a crawl and stop driving as soon as you can safely do so.

QUESTION NO: 28
Keep a copy of your vehicle inspection report in the vehicle for one __________
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A. day.
B. week.
C. month.
D. year.

Answer: A

Explanation:

You may have to make a written report each day on the condition of the vehicle(s) you drove. Report anything affecting safety or possibly leading to mechanical breakdown. The vehicle inspection report tells the motor carrier about problems that may need fixing. Keep a copy of your report in the vehicle for one day. That way, the next driver can learn about any problems you have found.

QUESTION NO: 29
Class D fires are fires in combustible metals and are extinguished __________
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A. by smothering, cooling or heat shielding using carbon dioxide or dry chemicals.
B. by cooling and quenching using water or dry chemicals.
C. using specialized extinguishing powders.
D. with nonconducting agents such as carbon dioxide or dry chemicals.

Answer: C

Explanation:

Class D fires are fires in combustible metals. The fire is extinguished using specialized extinguishing powders.

QUESTION NO: 30
Vehicles must be equipped with emergency equipment, including __________
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A. fire extinguisher(s).
B. spare electrical fuses.
C. warning devices for parked vehicles.
D. all of the above

Answer: D

Explanation:

When you conduct an inspection of your vehicle, make sure that your vehicle has the proper emergency equipment. Required emergency equipment includes fire extinguisher(s), spare electrical fuses (unless vehicle is equipped with circuit breakers), and warning devices for parked vehicles (for example, three reflective warning triangles).