cross a bridge when one comes to it

　　船到桥头自然直，临机应变(不要提前操心)

　　释义：

　　to worry about a problem when it actually happens and not before 临机应变(不用事前操心)

　　例句：

　　She says that she will cross that bridge when she comes to it.

　　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.