We _________there when our father died.
Đáp án D
Một hành động đang diễn ra ở 1 thời điểm trong quá khứ => thì quá khứ tiếp diễnWhich of the followings is NOT an evidence of monitoring studying?
Our flight was delayed, but the plane finally _______shortly after midnight.
Which of the followings is NOT badly affected by contaminated groundwater?
Which of the followings is the flow of water from the ground to the surface?
In the US, each company decides for itself (100) ________ to close or remain open on those days.