The scientist corresponds with colleagues in order to learn about matters ______ to her own research.
| A．relevant | B．Instant | C．resistant | D．important |
I travel to the Binhai New Area by light railway every day，________ do many businessmen who live in downtown Tianjin.
| A．as | B．which | C．when | D．though |
Jack wasn't saying anything，but the teacher smiled at him ________ he had done something very clever.(2011·湖南)
| A．as if | B．in case | C．while | D．thought |
—Did you return Fred's call?
—I didn't need to ________ I'll see him tomorrow.
| A．though | B．unless | C．when | D．because |
Leave your key with your neighbor ________ you lock yourself out one day.(2012·辽宁)
| A．as long as | B．even though |
| C．in case | D．as if |
A number of high buildings have arisen ________ there was nothing a year ago but ruins.(2012·山东)
| A．when | B．where | C．before | D．until |