It will be ___ great fun to have a picnic on ___mountain before we go home.

问题描述:

It will be ___ great fun to have a picnic on ___mountain before we go home.
A.a;the
B.a;/
C./;/
D./;the

D,fun不可数,不加冠词,mountain是特指某座山,用定冠词the