英和和英

a mandatory clause

compulsory branches

be the essential element

absolutely essential

to meet the need―fill a need―minister to one's needs

the essential requisites for the job

according to the need

more than is needed

of something, to be needed

to a vital degree

to urge （on one） the necessity of something―impress upon one the importance of something

the state of being absolutely required

obligate money

unnecessary

to provide one with needful things

the minimum required quantities

immediate needs

to cause necessity―necessitate

to provide against a possible need―provide against emergencies

privation

urgently needed

without any necessity

a crying need

action having to do with progress of action or matter (do more than is necessary)

It's necessary.

It is necessary.

material needs

not absolutely necessary

a condition of being unnecessary

to be self-sufficient