Q
98. Charge the trailer air brake system and check that the trailer rolls freely. Then stop and pull out the trailer air supply control valve. Pull gently on the trailer with the tractor to check that the trailer emergency brakes are on.
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Aa. This is how you test the trailer emergency brakes.
Bb. This is how you check the trailer tires for wear.
Cc. This is how you align the trailer with the tractor.
Detailed Explanation
The correct answer is "a. This is how you test the trailer emergency brakes.". This is based on federal CDL regulations and safety standards.
Correct Answer: a. This is how you test the trailer emergency brakes.
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