it's not easy to catch fish only with your hands.

问题描述:

it's not easy to catch fish only with your hands.

"it"在此处是作代词,代替后面的"to catch fish only with your hands",后面这个短语才是真正的主语.一般因为"to do something"成分太长,放在前面会使句子有头重脚轻的感觉,读起来也不方便,所以久而久之,it is adj.to...