---Thoseseniorcitizenscheatedshouldhavebeenwarnedofill...

问题详情：

 ---Those senior citizens cheated should have been warned of illegal fund-raising.

---       . But few could resist the temptation.

A. They were    B. They should

C. They must    D. They did

【回答】

A

知识点：动词时态与语态

题型：选择题