have .since did区别have .since have done?eg：I haven’t seen you sinc_英语解答

have .since did区别have .since have done?
eg：
I haven’t seen you since I’ve been back.
I haven’t seen you since I was back.

人气：129 ℃　时间：2019-11-20 23:04:11

解答

since解释为自.以来时,后面应接一个时间点,而不是表示过程的完成时哦,第一句是不是写错了?