船到桥头自然直。Let't cross that bridge when we come to it.引申为：既来之，则安之。不要对一件不确定的事情忧心忡忡，等问题来了，再去迎刃而解，否则会得忧郁症的。此成语有不同的变形，如：
1. Don't cross the bridge before you reach it.
2. Don't cross the bridge till you come to it.
3. Never cross the bridge until you find it.
e.g. Don't cross the bridge till you come to it, is a proverb old, and of excellent wit.
既来之，则安之，是一句很有道理的老话。
另cross的相关用法：
1. No cross, no crown. 无苦即无乐。
2. as cross as tow sticks（英）非常生气
3. on the cross 对角地，斜地；不光明正大，不公正，不老实
4. cross action（律）反诉
5. cross-cultural 交叉文化的；涉及多种文化的
6. crosswind 侧风
