The doctor advised Vera strongly that she should take a holiday but didn’t help.A. it B

问题补充：

The doctor advised Vera strongly that she should take a holiday, but didn’t help.

A. it

B. she

C. which

D. he

答案：

(答案→)A. it

B. she

C. which

D. he

解析：这里代词it指代前面所做的事。