你想告诉对方你的桌子上有面镜子，应说：
A.This is a mirror on my table.
B.There is a mirror on my table.
你想让对方看你的卧室，应说：
A.Look at my bedroom.B.Look my bedroom.
你想知道垃圾箱在哪里，应问：
A.What's the trash bin? B.Where is the trash bin?
There is a bridge the river.
A. onB. inC. over
There are bridges in the park.
A. someB. anyC. a