只能用which不能用that的情况

　　1. A miracle is something that seems impossible but happens anyway.

　　奇迹就是看似不可能，却发生了。

　　2. If you wait, all that happens is that you get older.

　　如果你等待，发生的只有变老。

　　3. When life gets hard and you want to give up, remember that life is full of ups and downs, and without the downs, the ups would mean nothing.

　　当生活很艰难，你想要放弃的时候，请记住，生活充满了起起落落，如果没有低谷，那站在高处也失去了意义。