Ôn thi Cấp tốc 789+ vào 10 môn Tiếng Anh (Đề 16)

Son Doong Cave ______ by a local man named Ho Khanh in 1991.

32/51

Son Doong Cave ______ by a local man named Ho Khanh in 1991.

is discovered

discovered

was discovered

discover