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Safely pulling double and triple trailers requires knowledge and skill. If you want to pull double or triple trailers, you must add the Doubles/Triples (T) endorsement to your Class A CDL. The Missouri doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The MO CDL doubles triples test covers the following sections of the Missouri CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this MO CDL practice test now to prepare for the actual test!
1.
If there is a fire and you are not sure what to use to put it out, you should:
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use a fire extinguisher.
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wait for firefighters.
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use water.
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2.
When transporting cargo, cargo securement must be checked within the first _____ miles of a trip and every _____ miles after.
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50; 250
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100; 150
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50; 150
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3.
Headache racks:
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can blind other drivers.
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help you keep weights within legal limits.
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protect you from being hit by your cargo.
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4.
When backing a trailer, you should turn the steering wheel to the right to make the trailer go left (or vice versa). Once the trailer starts to turn, you should:
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turn the wheel more in the direction you want to go.
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keep backing up.
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turn the wheel the other way to follow the trailer.
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5.
To make the brakes work, air brakes use:
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compressed air.
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hydraulic air.
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nitrogen.
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6.
If you become drowsy while driving, you should:
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drink plenty of coffee.
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open the windows to get some fresh air.
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take a break.
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7.
A low air pressure warning signal:
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is required on vehicles with air brakes.
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is required on all vehicles without air brakes.
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is optional on vehicles with air brakes.
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8.
The posted speed limit for a curve:
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may be too fast for many trucks or buses.
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is safe for all vehicles.
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is safe for trucks or buses, but it may be too fast for cars.
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9.
If your brakes fail on a steep mountain downgrade, you should:
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decide what to do as soon as you know your brakes do not work.
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slow down until your vehicle comes to a complete stop.
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stay on the road and keep looking for the next available escape ramp.
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10.
To prevent rollover, you should:
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go slowly around turns.
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keep the cargo as close to the ground as possible.
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All of the above.
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