We tried to persuade him to stay home but at last he went to the construction site desp

问题补充：

We tried to persuade him to stay home, but at last, he went to the construction site despite his bad illness.

A. in case

B. in vain

C. in fact

D. in addition

答案：

A. in case

(答案→)B. in vain

C. in fact

D. in addition

解析：考查介词短语。我们尽力地说服他呆在家里，但是徒劳的。故用in vain.