I like ( ) clouds in the sky.

答案为B
like doing sth、like to do sth 喜欢做某事.
I like (watching ) clouds in the sky
我喜欢看天上的云.
选c的话应该是
I like ( to look at) clouds in the sky.：look at ：看着.就像look at the blackboard一样
我喜欢看着天上的云
希望能帮到您.