cross that bridge when one comes to it, 字面的意思是“到了桥边再过桥”，其实就是指“等事情发生了再应对”，“船到桥头自然直”。

【例句】
Never mind that, we shall cross that bridge when we come to it.
别管那个，到时候再说吧，船到桥头自然直。

They don't want to start thinking about how to finance their daughter's veterinarian training yet. They prefer to cross that bridge when they come to it.
他们不要现在就开始为孩子上兽医学校准备学费，而是打算等孩子真上了再说。