Never before _______ so rapidly developing as it is today.
A. has our country been
B. our country has been
C. has been our country
D. our country hasn‘t been
查看答案
Look at this group of people ______ beach volleyball.
A. played
B. is played
C. playing
D. is playing
While _____ the book, he nodded from time to time.
A. reading
B. read
C. is reading
D. is read
He would have given you more help, if he ________ so busy.
A. have not been
B. had not been
C. not have been
D. not had been
Younger children are curious ________ how things workㄛand many of them want to take
A. of
B. about
C. at
D. with