It has been proved ____taking exercise regularly does good to one’s health

It has been proved ____taking exercise regularly does good to one’s health
It has been proved ____taking exercise regularly does good to one’s health

It has been proved ____taking exercise regularly does good to one’s health
that
it形式主语,后taking exercise regularly does good to one’s health 为真正主语,防止头重脚轻,所以用it 来当形式主语

that