John may phone tonight. I don’t want to go out ________ he phones.
A. as long as        B. in order to        C. in case        D. so that

 The day must be breaking, _____ the birds have begun singing.
   A. because              B. as               C. for                D. since

 --- Don’t look down upon Bob. He has his own advantages.
--- Oh, yes. ________ others are weak, he is strong.
A. If        B. When        C. Where        D. Though

 Someone called me up in the middle of the night，but they hung up ________ I could answer the phone.
A. as        B. since        C. until        D. before

 --- Is Mr. Smith in the office?
--- Yes，________ he is in charge of the office，he must be there.
A. since        B. however        C. whether        D. for

 The company has a free long-distance telephone number _____ customers may call with any questions they have about its products.
   A. although           B. as              C. even if             D. so that

 The class went on with the story _____ they had left it before the holiday.
   A. where            B. which            C. in which            D. when

 I had just started back for the house to change my clothes _____ I heard the voices.
   A. as               B. after              C. while              D. when

 I would appreciate it _______ you call back this afternoon for the doctor’s appointment.
A. until        B. if        C. when        D. that

 ____ he took part in the competition, he won a second prize.
   A. For the first time         B. At a time           C. At one time            D. The first time