It is good __us to do some physical exercise every dayA.of B.for

问题描述:

It is good __us to do some physical exercise every day
A.of B.for

你好。

答案是FOR,因为强调的是一般现象,一种规律。

如果是个别现象或者个别情况,我们就用of :
It was very good OF Mary to help a granny to cross the street.

for

It is good _B.for_us to do some physical exercise every day