由于餐厅人手不足，服务员这周不得不连续上两个班次。

The waiter had to work ___double-shifts this week because the restaurant was short-staffed.

疫情期间，护士们经常需要在照顾病人和消毒工作之间轮班。

During the pandemic, nurses often had to ___double-shift between patient care and disinfection duties.