below和under的区别

under 是用来说在什么下面，比如老板下面，水下面等等。

但是below 就比较的方位化了，比如信封的下面，图纸的下面等。

one of somali pirate ships is sailing past a chine vessel under potential attack.

below this description, there is a drawing which shows how to dig a hole.

below---在同一个平面上
under---在不同平面，立体的