come across偶然遇见，碰到；
come out开花，出版，出来；
come up走进，被提及；
come up with提出；
come about发生；
come to oneself苏醒；恢复知觉
How did it come about?
这事儿怎么来的？
She has a mental toughness that did not come about by chance ．
她坚韧的精神并非偶然。
It\'s here that we come up against the difference of approach
我们就是在这一点上面临方法上的分歧。
