After working for a long time,.但为什么是Having working for a long time.

问题描述:

After working for a long time,.但为什么是Having working for a long time.

因为for是介词..后面加动词要用现在进行时`

因为吧
你已经work了 完成那段work了

没有Having working for a long time.
只有以下两个:
Having worked for a long time.
Having been working for a long time.
这种用动名词开头的句子很多的.