last: to continue existing or happening很多时候可以和continue互换
last作为动词表示“持续”，它的主语一般是一个事件，情形，问题。
生活中总是充满了起起落落，没有什么是一成不变的
翻译：Life is always filled with ups and downs,and nothing will last for good.
场景1：初恋 We always find it very difficult to forget our first love .It always lasts for a long time or even forever.
场景2：The terrible weather has lasted for a week.
