If water and compressor oil are left to build up in an air brake system, the system can be damaged. Air storage tanks are equipped with drains to allow this accumulation to be removed. Manually controlled drains should be operated at the end of each day of driving.

Are necessary for the proper function of the system.

Should take up about 10 percent of the tank.

If the low pressure warning signal activates while you are driving, it is important that you safely exit the roadway as soon as possible and park your vehicle. If the air pressure gets too low, the brakes will no longer work well enough for you to stop safely.

Exit the roadway as soon as safely possible

You must have a hazardous materials endorsement to transport any hazardous materials that require the vehicle to be placarded.

Need to obtain a hazardous materials endorsement.

Need to drive while using flashing lights.

To obtain a hazardous materials endorsement, you must be a U.S. citizen or lawful permanent resident. You will lose your hazardous materials endorsement if you renounce your U.S. citizenship.

A U.S. citizen or permanent resident.

Perform their own background check.

Transporting cargo that is loaded with a high center of gravity increases the risk that the transporting vehicle will tip over. Cargo should be loaded with a safe weight distribution.

Increases the likelihood of a rollover.

Increases the likelihood that items will fall down.

Increases the difficulty of unloading the cargo.

When approaching a long downgrade, you should shift into a lower gear then use proper braking techniques. Using the brakes alone could cause them to overheat and fail. The braking power of the engine, which is maximized by being in a lower gear, will be the principal way of controlling your speed on a downgrade.

Downshifting and then using the brakes.

Mostly using the brakes and occasionally downshifting.

Downshifting and then using the brakes.

Roads are often especially slippery when it first begins to rain. Rainwater forms a slick film when mixed with oil and grease on the road surface that has not yet washed away.

The water mixes with oil and grease on the road.

Tires are not made to drive in wet weather.

The water yet hasn't absorbed the dirt and grease.

Class A Driving Test | Oklahoma 2025 #1 Page 7 of 7

Train for FREE online with our Oklahoma class A license test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a OK CDL class A permit in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that CDL class A requirements may vary from state to state.

Number of Question 50

Passing Score 40

Number of Tests 20

Class A Driving Test | Oklahoma 2025 #1 Page 7 of 7

43 . Some water and compressor oil is usually found in the compressed air within an air brake system. The water and compressor oil:

44 . You should ____ if the low pressure warning signal activates while you are driving.

45 . If you plan to transport hazardous materials, you will:

46 . To obtain a hazardous materials endorsement, a person must be:

47 . When it is difficult to see and you are traveling near other drivers, you should:

48 . Having weight loaded in a way that creates a high center of gravity:

49 . When driving on a long downhill slope, you should brake by:

50 . Roads are especially slippery right after it begins to rain because:

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