They think ________ possible to learn a foreign language while studying in the middle school．

They think ________ possible to learn a foreign language while studying in the middle school．

A.we are

B.this is

C.it

D.that

答案及解析： C

解析：

think/believe it+adj．结构，句中的it是形式宾语，真正的宾语是后面的不定式。