Accordingtoastudy,someseriousroadaccidentsusuallyhappe...

问题详情：

 According to a study, some serious road accidents usually happen in the last few hours before dawn, when even the most experienced driver has difficulty        awake.

A. maintaining   B. preserving   C. claiming     D. staying

【回答】

D

知识点：单词

题型：选择题