after that是什么時態的標志

　　The funny thing is it never happened again after that.

　　奇怪的是從那以后這事再也沒有發生過。

　　She was in the hospital for a week and laid up for a month after that.

　　她住院一星期后又臥床一個月。

　　After that, food shipments to the port could begin in a matter of weeks.

　　之后，到該港口的食物運送可能在幾周之內開始。