Question

Experiments related to the sense of smell are more easily 　　　 than those related to perception of color.?

A.setting them up　 B.to set up ?

C.set up　　　　　　 D.set up those

Answer 1

C

主句谓语动词是被动语态，easily是副词，修饰set up。(注意，在考试中还有一个经常考的考点是“主语+系动词+不定式”表示被动意义，如The book is easy to read。easy是形容词，所以后面用不定式。