Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Not until the end of the 19th century ______ become a scientific discipline.
A. plant breeding has
B. did plant breeding
C. plant breeding had
D. has plant breeding
Đáp án là B.
Sử dụng cấu trúc : Not until + time + did + S +V = It was not until + time that S + Ved: Tận cho đến khi…