If I had enough time and money, I would go travelling with you.
如果我有足够的钱和时间，我会和你一起去旅行。
If I left, I would tell you beforehand.
如果我要离开，我会先告诉你。
If I lost one opportunity, I would try to find another one.
如果我错失一次机会，我会想办法寻找另一个机会。