It’s been a week after we left your family and we are now back home.after为什么不可以改成that?
问题描述：
It’s been a week after we left your family and we are now back home.after为什么不可以改成that?
答
这里既不能用after,也不能用that,而应该用since,因为只有用了since,主句才可能用现在完成时.