A. used to
Đáp án A
“used to”: đã từng (giờ không còn nữa)
Câu phía sau “Now everything has become completely different.” Tức là câu phía trước mang nghĩa đã từng xảy ra trong quá khứ
Scientists are unsure of the reason for this (70)_______ on the global scale either.
In this way, we can put you in a (59)_________ at the most suitable level.
The trains which go through the Chunnel can travel at up to 300km/h due to the(31)_________ electrical system.
At 23 he move to Atlanta and took (52) _________ odd jobs as he started working on his stage career.