______the students in our class is 50 an
问题:
______the students in our class is 50 and ______them study hard [ ]
A. The number of; the number of
B. A number of ; the number of
C. The number of ; a number of
D.A number of ; a number of
______the students in our class is 50 and ______them study hard [ ]
A. The number of; the number of
B. A number of ; the number of
C. The number of ; a number of
D.A number of ; a number of