高中英语语法独立主格结构的时态问题
问题描述：
高中英语语法独立主格结构的时态问题
请问独立主格结构结构除了常见的4种,能否用sb having been doing?.（现在完成进行时）~请给出依据,
答
肯定是可以的
It having been raining for several days,we had to cancel the trip to Beijing.