I don't think () possible to master a foreign language without much memory work

问题补充：

单项选择题:

I don think () possible to master a foreign language without much memory work.

A．this

B．that

C．its

D．it

答案：

答案：D

解析:it做形式宾语，真正的宾语为to master a foreign language without much memory work。故选D。