v-ing做状语,主句谓语动词是过去式的话,状语为having done,和v-ing的区别

I came in smling.came 与 smiling 发出的动作几乎同时进行.Having worked for 2 hours,he stopped to have his meal.在工作了两个小时之后,他停下来去吃饭.having worked 与 stopped ,worked这个动作发生在stopped...