A red sky in the morning _____ to be a sign of bad weather.
| A．says | B．is saying |
| C．has said | D．is said |
I have a tight budget for the trip，so I'm not going to fly ________ the airlines lower ticket prices.(2012·上海，32)
| A．once | B．if | C．after | D．unless |
________，Carolina couldn't get the door open.
| A．Try as she might | B．As she might try |
| C．She might try as | D．Might as she try |
________ the jewels were locked in a strong box，the thieves stole them without any difficulty.
| A．If | B．Unless | C．Although | D．Because |
________ he comes or not，the result will be the same.
| A．Even if | B．Whether | C．No matter | D．Although |
________ volleyball is her main focus，she's also great at basketball.(2011·北京)
| A．Since | B．Once | C．Unless | D．While |