structure ：verb+“一下”
a polite and gentle way to ask someone to do something for a short while.
wait a minute/等一下
stop for a while/停一下
take a look/看一下
show a smile/笑一下
have a taste/尝一下
have a listen/听一下
write down/写一下
read it/念一下，
say something/说一下，
blow for a while/吹一下
breath for a while/呼吸一下
relax for a while/放松一下
come over/过来一下