---Doyouknowthereason

问题详情：

--- Do you know the reason _________ pilots turn off the plane’s lights before taking off?

---The practice is for the passengers to adjust to the dark _________ an emergency.

A．why; for fear that                  B．for which; in case of

C．how; for fear of                   D．that; in case

【回答】

B

知识点：介词

题型：选择题