In the swimming race, three boats will be in case of an emergency.
A. standing by
B. turning on
C. getting on
D. running on
网友回答
A. standing by
B. turning on
C. getting on
D. running on
解析： 题意：有有三只船严阵以待，预防紧急情况。stand by 准备行动；待机；turn on 打开；get on进展；run down撞倒。