Is it always easier _____friends than to keep them?A.making B.make C.to make D.made

C，形式主语

C.to make
前后要对应嘛

C ,对称结构。

C
it is +adj(形容词)+to ...
固定结构

c. 因为要前后一致。后面是 to keep them，所以前面应该选带to的不定式

Is it always easier _____friends than to keep them?
C , 后面是to keep,前面也要对应是to do结构才能比较

是不是交朋友总是比和朋友相处简单？