Question

【题目】The nurse won't leave her patients she's sure they are all taken care of.

A. unless B. because C. since D. if

Answer 1

【答案】A

【解析】句意：这个护士不会离开她的病人，除非她确定病人们都被照顾得很好。because因为，引导原因状语从句；since自从，引导时间状语从句；既然，引导原因状语从句；if如果，引导条件状语从句；unless除非，如果不，引导条件状语从句。根据句意可知，这里考查的是从属连词unless，故选A。