bì yào
necessary
essential
indispensable
required
méi yǒu bì yào
there is no need to (do sth)
bì yào tiáo jiàn
requirement
necessary condition (math)
shā jī hé bì yào yòng niú dāo ne
don't use a sledgehammer to crack a nut
de minimis non curat praetor (trivial matters are of no concern to a high official)