WHEN I WAS YOUNG, THE RIVERS _____ CLEANER THAN THEY ARE NOW.A. USE...

20.

When I was young, the rivers _____ cleaner than they are now.

A. use to being

B. used to be

C. used to being

D. use to be

Chọn phương án (A hoặc B, C, D) ứng với từ/cụm từ có gạch chân cần phải sửa: