HÃY CHỌN MỘT ĐÁP ÁN ĐÚNG NHẤT (A, B, C HOẶC D) CHO MỖI CÂU SAU

80. I suddenly ________ the Tower Square. I ________ there ten years before.

A. recognized / was B. was recognizing / was

C. recognized / had been D. had recognized / had