四六级考试

【单选题】 I was so tired that I _________ when I was sitting in the armchair reading.
A．dropped away
B．dropped out
C．dropped off
D．dropped through

网考网参考答案：C
网考网解析：
drop off指“打瞌睡，睡着”，符合句意：drop away指“减少”；drop out指“(参加比赛等)弃权，(从事或即将从事某项活动等之人)不参与，放弃”；drop through是口语用法，指“毫无结果，不再被讨论”。 查看试题解析出处>>