英和和英

attendance is mandatory

attendance is obligatory

have need of

people in need

It's necessary.

have as a necessary feature

in submission to his needs

It is necessary.

to be necessary

an essential thing that one cannot do without owning

immediate needs

something that is vitally necessary

Need to confirm

if there happens to be need

You will be required to do so.

according to the need

Is required

It take many men―requires a number of hands.

We require many hands.

of something or someone, to be an absolutely necessary part of something

be used or required for

by necessity

be the essential element

that must be expected

to be provided with necessities

just as it should be

to meet a need

suitable to your needs

meet a need

iron is absolutely necessary