wake-up call
noun
1- chiefly N. Amer. a telephone call notifying the person called that a previously agreed time to wake up has arrived〈主北美〉催醒电话。
1.1
- figurative a person or thing that causes people to become fully alert to an unsatisfactory situation and to take action to remedy it〈喻〉令人惊醒的人（或物）：
today's statistics will be a wake-up call for the administration.
今天的统计数字将引起政府的警觉。