2024 NC CDL Practice Test: Class B - Test 4 Based on 2024 NC CDL Handbook 3. The air compressor is connected to the engine through ______. A A very short tube. B Gears. C None of the listed answers. D A V-disc. Next More 3/29 Progress 0 Errors Restart Next Next Class B - Test 4 Back to Test List Class B - Test 3 Class B - Test 5 Challenge Library 12 More NC CDL Practice Tests 13 Class B - Test 5 14 Class B - Test 6 15 Class B - Test 7 16 HazMat - Test 17 HazMat - Test 2 18 HazMat - Test 3 19 HazMat - Test 4 20 HazMat - Test 5 21 HazMat - Test 6 22 Passenger - Test