Throughout history, water had been people’s slave and also their master.
Throughout history, water had been people’s slave and also their master.
A. Throughout
B. had been
C. people’s
D. and also
Đáp án B
Had been -> has beenThì hiện tại hoàn thành diễn tả hành động xảy ra ở quá khứ và vẫn còn kéo dài đến hiện tại
