The chairman thoughtnecessary to invite Professor Smith to speak at the meeting .A. thatB.

问题补充：

The chairman thoughtnecessary to invite Professor Smith to speak at the meeting .

A. that

B. it

C. this

D. him

答案：

A. that

B. it

C. this

D. him

解析：

本题考查it作形式宾语，代替to invite Professor Smith to speak at the meeting，其他选项均不可以充当形式宾语。