Practice question What is a jackknife? A cargo paperwork shortcutAn action not supported by DPS Section 7Units skid or fold into an angle with each otherA passenger endorsement only Answer: C — Units skid or fold into an angle with each other 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 →