-I wonder how much you charge for your services.-The first two are free_________

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-I wonder how much you charge for your services.
-The first two are free____________ the third costs $ 30.    [     ]
A. while
B. until
C. when
D. before

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举一反三

Adults are usually easy to ignore some common things __________little children tend to notice them.   [     ]
A. when
B. while
C. as
D. though

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Mary was on the point of leaving the room ___________the telephone rang.[     ]
A. when
B. while
C. as
D. but

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Work hard________ you will succeed.   [     ]
A. and
B. so
C. or
D. or not

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Do come on time this evening, _________you will miss theperformance.    [     ]
A. and
B.or
C. so
D. but

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You have failed two tests. You"d better start working har- der,________you won"t pass the course. [ ]

A. and
B. so
C. but
D. or

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