there be 和used to

题目

there be 和used to
there uesd to be a buiding here.
变否定,一般疑问句及回答
There didn't use to be a building here.
Did there use to be a building here?
Yes,there did.
No,there didn't.
还是
There uesdn't to be a buiding here.
There isn't uesd to be a buiding here.
Was there ues to be a buiding here?
Yes,there was.
No,there wasn't.

答案

答案是
There didn't use to be a building here.
Did there use to be a building here?
Yes,there did.
No,there didn't.
很明显,用过去时.