Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
Hardly did he enter the room when all the lights went out.
Giải chi tiết:
did he enter => had he entered
Cấu trúc: Hardly had S+ Ved when S + Ved/ V2 [ Ngay khi...thì...]
Population growth rates vary among regions and even among countries within the same region.
Around 150 B.C. the Greek astronomer Hipparchus developed a system to classify stars according to brightness.