There used to be a tree near the house.如何变成反意疑问句

问题描述:

There used to be a tree near the house.如何变成反意疑问句

Did there use to be a tree near the house,did there?

There used to be no trees near the house

Isn't there used to be a tree near the house?

usedn't there?

有两种改法:
There used to be a tree near the house,didn't there?
There used to be a tree near the house,usedn't there?