题目

In the cross-lake swimming race, a boat will be ____in case of an emergency. A. standing by          B. turning on        C. getting on           D. running on 答案：A 解析: 句意：有船只严阵以待，预防紧急情况。stand by 为不及物短语：to wait and be ready for action if needed 准备行动；待机；turn on 打开；get on进展；run down撞倒。根据句意，B 、C、D 三项均不符合。

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