There lots of trees on both sides of this street.But now they are all gone.A. used to hav

问题补充：

There lots of trees on both sides of this street.But now they are all gone.

A. used to have

B. are used to be

C. used to be

D. are used to have

答案：

A. used to have

B. are used to be

(答案→)C. used to be

D. are used to have

解析：be used to sth习惯于某事;used to do sth过去常常做某事.结合下文可知句意为：这条街两边过去常常有许多树。故选C。