单选题 The mayor was forced to ______ when the city's employees' union threatened a strike ______ any of its members were fired.
【正确答案】 A
【答案解析】句意：当该市的工会威胁说如果其任何一个成员被解雇，就进行罢工时，市长被迫做出了让步。back down退让，让步。count on依赖；依靠；期望。bring off使脱离险境；成功完成。drop out离开，退出。