The police officers in our city work hard the rest of us can live a safe life. A. in case

问题补充：

The police officers in our city work hard the rest of us can live a safe life.

A. in case

B. as if

C. in order that

D. only if

答案：

A. in case

B. as if

(答案→)C. in order that

D. only if

解析：A以防，万一B似乎，好像C为了，目的是D只有……(才)；唯一的条件是……”句意：警务人员在我们城市里辛勤工作目的是使我们能过着安定的生活。