—He must be busy doing his homework right now.　　—I imagine.A. thatB. toC. soD. it

问题补充：

—He must be busy doing his homework right now.

—I imagine.

A. that

B. to

C. so

D. it

答案：

A. that

B. to

(答案→)C. so

D. it

解析：I imagine so=I think so