—Are these your sheep ?—No. Mine _____ on grass at the foot of the hill.
A. are feeding
B. feed
C. is fed
D. is feeding
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—Is there anybody in the classroom ?—No, the teacher, together with the students _____ to the playground.
A. go
B. went
C. has gone
D. have gone
How time flies! Ten years ________ passed
A. have
B. has
C. is
D. are
Many a student ___that mistake before.
A. had made
B. has been made
C. have made
D. has made
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