2024 WV CDL Practice Test: All - Test 2 Based on 2024 WV CDL Handbook 28. A combination vehicle has two air lines: the emergency line and ______. A The service line. B The air supply. C The air line. Next More 28/29 Progress 0 Errors Restart Next Next All - Test 2 Back to Test List All - Test All - Test 3 Challenge Library 12 More WV CDL Practice Tests 37 All - Test 3 38 Tank and Hazmat - Test 39 Tank and Hazmat - Test 2 40 Class C - Test 41 Class C - Test 2 42 Class C - Test 3 43 Class C - Test 4 44 Class C - Test 5 45 Bus - Test 46 Bus - Test 2