There must be a dog sitting behind it .为什么sit 后面加ing
问题描述:
There must be a dog sitting behind it .为什么sit 后面加ing
答
sitting behind it 为独立主格结构,在这里做表语补足语.
There must be a dog sitting behind it .为什么sit 后面加ing
sitting behind it 为独立主格结构,在这里做表语补足语.