There's no way of knowing why the man fails，____ he is always hard-working and wise．
A．when B．although
C．if D．unless
--Shanghai Pudong Airport please! I must get there by 7．
--____，but I'll try my best．
A．No problem B．All right
C．I can't promise D．I can't do that
The research group ____ 15 members has made great achievements in recent years．
A．is made up of B．makes up
C．made up of D．making up of
When the star fell ____ the darkness quickly at night，all the people felt it amazing．
A．down B．off
C．behind D．through
It's an either-or situation．You can watch TV or play games，but you can't do ____．
A．others B．either
C．another D．both
--I'd like to book a room for tonight．
--Sorry，sir，but we don't have any rooms ____ right now．
A．able B．comfortable
C．available D．suitable
