19..Someone is at the door who is?20.A. this　　　B. that　　　C. it　　　D. He

问题补充：

19..Someone is at the door, who is?

20.

A. this

B. that

C. it

D. He

答案：

A. this

B. that

(答案→)C. it

D. He

解析：可联系答.案.网客服索取。