The first step is finished. What do you suggest next?A. should doB. be doneC. to doD. doi

问题补充：

The first step is finished. What do you suggest next?

A. should do

B. be done

C. to do

D. doing

答案：

A. should do

B. be done

C. to do

(答案→)D. doing

解析：suggest doing sth.意为“建议做某事”。