肯定式：there（ ）some books on the shelves
问题描述：
肯定式：there（ ）some books on the shelves
否定式：there（ ）【isnt】a bag on the desk.
there（ ）【arent】any books on the shelves、
疑问式简略回答：（ ）there a bag on the desk?yes,there（ ）.
( )there any books on the shelves?
yes,there( ）.No,there( )
答
肯定式：there（are ）some books on the shelves
否定式：there（isn't ）a bag on the desk.
疑问式简略回答：（Is）there a bag on the desk?yes,there（ is）.
( Are)there any books on the shelves?
yes,there (are）.No,there (isn't)