61. After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is done by:
Applying and releasing the trailer brakes and listening for the sound of the brake.
62. Before you back under a trailer, make sure that:
The trailer brakes are locked.
63. How should you test the tractor semitrailer connection for security?
Pull gently forward in low gear against the locked trailer brakes then look at it carefully.
64. The front trailer supports are up and the trailer is resting on the tractor. Make sure:
Both a and b are correct.
65. To unlock the fifth wheel the locking lever should be placed in the ____ position.
Open.