THE WORD "THEY" IN THE 2ND PARAGRAPH REFERS TO A. AUTHORS...

39. - DE THI THU THPT QUOC GIA NAM 2017 MON TIENG ANH TRUONG THPT QUANG XUONG 1 THANH HOA LAN 1 CO DAP AN
Tiếng Anh DE THI THU THPT QUOC GIA NAM 2017 MON TIENG ANH TRUONG THPT QUANG XUONG 1 THANH HOA LAN 1 CO DAP AN

39. The word "they" in the 2

nd

paragraph refers to

A. authors B. efforts C. counterparts D. sources