The preparations ________ by the time the guests ________ .
Đáp án C
Chủ điểm ngữ pháp: sự phối hợp các thì
S+ had+pp, + when/ by the time + S + V_ed: một hành động kết thúc trước khi hành động khác xảy ra trong quá khứ.
Mọi sự chuẩn bị đã hoàn thành khi khách mời tới.
Ann's encouraging words gave me _________ to undertake the demanding task once again.
He did not share his secrets with other people but he ________in her.
The local people insisted that the road_________50 cm more so that, in case of flood, they still can travel on it.
The girl __________ design had been chosen stepped to the platform to receive the award.