问题补充:
单选题Inthecross-lakeswimmingrace,aboatwillbe____incaseofanemergency.A.standing byB.turning onC.getting onD.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。