要看你的句子主语是什么了.如果主语是一件实际的事情,后面就用be beneficial to doing sth.
如：Reading a lot is beneficial to (improving) your english.
但是如果主语是it 作为形式主语,那么通常后面用不定式作为真正的主语,即用be beneficial to do sth.如：It is beneficial to read a lot.=to read a lot is beneficial (to you).
以下类同.
有问题欢迎追问~