专题限时训练(十四) [连词与状语从句]
(限时：10分钟)
1．In Boston on April 15，2013，a marathon race was going on ________an explosion happened, claiming a lot of lives.
A．while B．when
C．after D．before
2．The new system needs to be in operation for five months ________ it can be updated.
A．as B．while
C．before D．once
3．________， as long as I'm with nature, I don't care.
A．However tough the journey is
B．Whatever tough the journey is
C．However the jou rney is tough
D．Whatever the journey is tough
4．Jerry has promised to keep the secret , so he won't tell anyone ________ asked to.
A．until B．now that
C．unless D．even though
5．Bicycling is good exercise; ________， it does not pollute the air.
A．nevertheless B．therefore
C．otherwise D．besides
6．Life is filled with things we have no control over, ________ ourselves, we can control.
