I'll go to the library as soon as I finish what I A. was doingB. am doingC. have doneD. ha

问题补充：

Ill go to the library as soon as I finish what I

A. was doing

B. am doing

C. have done

D. had been doing

答案：

A. was doing

(答案→)B. am doing

C. have done

D. had been doing

解析：