. The old couple tried to some extra money for some purpose.A. set asideB. set outC. set b

问题补充：

. The old couple tried to some extra money for some purpose.

A. set aside

B. set out

C. set back

D. set up

答案：

(答案→)A. set aside

B. set out

C. set back

D. set up

解析：短语辨析。A. 留出，不顾 B. 出发，开始 C. 推迟，使……受挫折 D. 建立，开业。句意：这对老夫妇努力留出一些额外的钱作为他用。故选A。