在汽车空调系统中,属于碳氧化合物制冷剂的有()。
A.氨
B.水和二氧化碳
C.氟里昂
D.甲烷
E.乙烯
参考答案:D, E
I don't trust that man; he is the guy who ____. [ ]
A. never eat his word
B. never keeps saying
C. always eats his words
D. keeps his word
五阶段模型排列顺序正确的是()。
A.形成→规范→震荡→执行→终止
B.形成→震荡→规范→执行→终止
C.形成→执行→规范→震荡→终止
D.形成→震荡→执行→规范→终止