occur to和 become of 有什么区别

occur to 可以用在什么事发生在了什么人的身上。比如说，something sad occurred to him. 就是说，他发生了一些悲伤的事情
而become of是变成的意思。比如说某某东西或人变成了某某东西。例子是，be a lawyer become of his dream