21. You have pushed the trailer air supply valve. You should not back a tractor under a trailer until the whole air system is:
At normal pressure.
22. You are coupling tractor to a semi-trailer. You have connected the airlines. Before backing under the trailer you should:
Supply air to the trailer system, then pull out the air supply knob.
23. You are coupling a tractor to a semi-trailer and have backed up but are not under it. What should you hook up before backing under?
The emergency and service lines.
24. Tractor with ___ trailer requires the shortest amount of stopping distance.
Fully loaded.
25. There are two things that a driver can do to prevent a rollover. They are: (1) keep the cargo as close to the ground as possible; and (2):
Go slow around turns.