( )21. — Is n’t he a good student?
— ___________. He studies hard.
A.No, he is. B.Yes, he is. C.No, he isn’t.
( )22.The_____ of the story is very interesting, but it become boring later.
A.beginning B.begin C.start
( )23.You are right. I agree_____ you.
A.on B.with C.to
( )24.The baby was sleeping________her mother opened the door.
A.as B.while C.when
( )25.I called you yesterday, but nobody ______ the phone.
A.checked B.answered C.took
