问题补充:
单选题Thegovernmentis_____andwilltakethenecessarystepstomaintainsecurityandstability.A.on the alertB.out of controlC.on guardD.in vain
答案:
A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。