1.Which condition indicates that a condenser may need replacement?
1.哪种情况表明冷凝器可能需要更换？
2.When must a technician evacuate (pull a vacuum on) the refrigerant lines?
2.技术人员必须对制冷剂管路进行抽真空（排气）的操作是在何时？
3.Which statement about propane is correct?
3.关于丙烷的哪项陈述是正确的？
4.Which hand signal instructs a crane operator to lower the cable?
4.哪种手势信号指示起重机操作员降低钢索？
5.The primary difference between a contactor and a motor starter is:
5.接触器与电机起动器之间的主要区别在于：
6.The term “bleed-off” refers to:
6.术语“排污”（bleed-off）是指：
7.What is the main function of a suction line accumulator?
7.吸气管储液器（accumulator）的主要功能是什么？
8.Which refrigerant replaced R-22 in modern systems?
8.在现代制冷系统中，哪种制冷剂取代了R-22？
