be good for 值得,对...有好处

用哪个be动词要看主语是单数还是复数,单数用is,复数用are。

例句:Doing exercise everyday is good for me to keep healthy. 这里doing exercise就代表单数。

be与情态动词的连用 其用法为:情态动词+系动词be原形。

Oh, great! That'll be good for Fergus.