水落石出
when the water subsides the rock emerge,
the whole thing comes to light
辩论个水落石出argue the matter out
查个水落石出get to the bottom of a matter; investigate sth. thoroughly
弄个水落石出get to the bottom of the matter
她起了疑惑，便决定弄个水落石出。She got suspicious and decided to get to the bottom of it.
把事情争个水落石出argue a matter out
他要是钻一个问题，就非钻个水落石出不可。When he digs into a problem he does not give up until he gets to the bottom.
我一定要把这事查个水落石出。I’ll be sure to investigate this matter thoroughly.