He smiled politely ________ Mary apologized for her drunken friends.(2012·山东)
A．as B．if C．unless D．though
(2013·重庆，25)________ we have enough evidence，we can't win the case.
A．Once B．As long as C．Unless D．Since
(2013·四川，7)He is so busy.He cannot afford enough time with his son________he wants to.
A．even if B．as if C．because D．before
(2013·陕西，18)I have heard a lot of good things about you ________ I came back from abroad.
A．since B．until C．before D．when
(2013·山东，28)________I have to give a speech，I get extremely nervous before I start.
A．Whatever B．Whenever C．Whoever D．However
(2013·山东，26)Mark needs to learn Chinese________his company is opening a branch in Beijing.
A．unless B．until C．although D．since
