2019年mpa考试英语真题——介词和介词短语684

{01}The government is _____ and will take the necessary steps to maintain security and stability.
A.on the alert
B.out of control
C.on guard
D.in vain
解析：　on the alert (="alert;" watchful; careful) 警惕，小心：Drivers must be on the alert for traffic signals. (="Drivers" must be especially careful to see signals when driving a car.) (司机必须密切注视交通信号。)out of control 失去控制；on guard站岗；in vain 徒劳，无效。
本题选A。