It's comfortable_______ on the sofa.A.sat B.sitting C.to sit

问题描述:

It's comfortable_______ on the sofa.A.sat B.sitting C.to sit

c 类似的还有 :It's easy /difficult to learn.等一类的。符合it's+形容词 +to do 结构

选C,it is comfortable to do sth

选B sitting
it 作为形式主语代替后面的sitting on the sofa
原句可以改为:Sitting on the sofa is comfortable....
采纳我的吧~楼主~

sitting

B、
Sitting on the sofa is comfortable~