请问beat on和beat against的区别,什么时候用哪个

题目

请问beat on和beat against的区别,什么时候用哪个
可是我在牛津句库里看到过beat on的这样的例句啊?:
He beat on the door with the flat of his hand.
有点晕了

答案

beat against是撞上,打上
eg：The rain beat against the windows.
雨水拍打在窗户上.
beat on是火般照晒
eg：The sun continued to beat on them.
阳光持续火辣辣的晒着大地.