______ gathering and storing information, the computer can also solve complicated problems. A: Not only B: B．Unless C: C．Except D: D．Besides

Don't leave the building ____ to do so. A: unless are instructed B: unless instructed C: unless being instructed D: unless to have been instructed

Our future offers will include your 2% commission _____.（ ） A: unless otherwise state B: unless otherwise informed C: unless informed D: unless otherwise stated

A man does not know the difficulty of anything________it personally. A: if he does B: unless he will do C: unless he does D: unless he does not do

It was ______ then that he realized the importance of a good mastery of computer. A: not until B: until C: unless D: not unless

Please don't call me at the office _______ it's really necessary. A: if B: unless C: unless if D: Except

He will never pass the final exam ______ he _______ harder. A: if, study B: if, studies C: unless, studies D: unless, study

All quotationsare subject to our final confirmation ______ otherwise ______. A: unless ...stating B: unless ... stated C: if ... stating D: once ... stating

The machine is so old ____ it can’t be used any more ____ some of its parts are changed. A: as ; unless B: that ; unless C: that; if D: whether ; or

6. A: but B: or C: or else D: unless