He smiled politely ________ Mary apologized for her drunken friends.(2012·山东，27)
A．as B．if
C．unless D．though
I don’t believe we’ve met before，________I must say you do look familiar.
(2012·新课标全国，25)
A．therefore B．although
C．since D．unless
It’s not easy to change habits，________ with awareness and selfcontrol，it is possible. (2013·重庆，23)
A．for B．or
C．but D．so
Don’t turn off the computer before closing all programs，________ you could have problems. (2013·北京，22)
A．or B．and
C．but D．so
I was glad to meet Jenny again，________ I didn’t want to spend all day with her.
(2013·大纲全国，23)
A．but B．and
C．so D．or
She says that she’ll have to close the shop ________ business improves.(2013·江西，28)
A．if B．unless
C．after D．when
