needful
adjective formal uk/ˈniːd.fəl/ us/ˈniːd.fəl/
需要的，必需的
necessary
We must not put them in more danger than is needful. 我们一定不能让他们处于不必要的危险中。
需要…的
needing something
They are needful of affection. 他们需要关爱。
do the needful UK old-fashioned or Indian English做必需做的事
to do what is necessary in a situation
Notify your bank and they will do the needful. 通知你的银行，他们会处理该办的手续。
Kindly do the needful at your earliest convenience.
Please do the needful and take appropriate action.
He had given me firm assurances that he would do the needful.
I suppose there's no sense in putting it off further. Time to do the needful.