Definition: all day and all night Level: C1
在重大活动期间，紧急服务全天候运行。
Emergency services operate ___round ___the ___clock during major events.
许多专业人士为了赶项目截止日期而全天候工作。
Many professionals work ___around ___the ___clock to meet project deadlines.
客服热线全天候有人值守以提供客户协助。
The support hotline is staffed ___around ___the ___clock for customer assistance.
