Practice question Where should a set be parked before uncoupling? A cargo paperwork shortcutAn action not supported by DPS Section 7Straight on firm, level groundA passenger endorsement only Answer: C — Straight on firm, level ground The correct answer is shown above. Try the full quiz for additional practice. Practice more: TX CDL Doubles and Triples Practice Questions - Texas CDL Doubles and Triples Endorsement Test Exam →