托业考试

根据网考网考试中心的统计分析，以下试题在2018/5/28日托业考试习题练习中，答错率较高，为：67%
【单选题】Passengers may retrieve their items from the overhead locker ______ the safety belt sign has been switched off.

• (A) meanwhile
• (B) under
• (C) although
• (D) once