THEY HAVE MADE A LOT OF PROGRESS ………….. THE COUNTRY BECAME INDEPEND...

6. - TONG HOP KIEN THUC TIENG ANH THCS VA CAC BAI KIEM TRA THU
TONG HOP KIEN THUC TIENG ANH THCS VA CAC BAI KIEM TRA THU
6. They have made a lot of progress ………….. the country became independent.A. for B. since C. before D. until