Bộ 5 đề thi giữa kì 2 Tiếng Anh 12 Global Success có đáp án (Đề 2)

People are allowed to swim in the bay, _______ they don't touch the coral reefs.

18/40

People are allowed to swim in the bay, _______ they don't touch the coral reefs.

although

whether

provided that

unless

Giải thích

Chọn C