CDL Combination Vehicles Practice Test Results

Question 1
90% answer correctly
How would a driver supply air to trailer air tanks?
Activate the service line
Push in the trailer air supply valve
Pull out the trailer air supply valve
Activate the air generator
Question 2
92% answer correctly
On a combination vehicle what color is the emergency air line?
Black
Red
Yellow
White
Question 3
75% answer correctly
The locking jaws should close around the __________ of the kingpin.
Neck
Top
Base
Shank