The number of people traveling by air has been growing _______. A. by leaps and bounds B. from time to time C. slow but sure D. by hook or by crook
Giải thích
Đáp án A
By/in leaps and bounds: tiến bộ nhanh
From time to time: thỉnh thoảng
By hook or by crook: bằng bất cứ cách nào