From facts，scientists have ________that more energy is being absorbed from the sun，throwing the earth's energy “out of balance”．
| A．confirmed |
| B．concluded |
| C．concentrated |
| D．centered |
You can borrow my car ________ you promise not to drive too fast.(2012·江西，31)
| A．unless | B．even if |
| C．in case | D．as long as |
One's life has value ________ one brings value to the life of others.(2012·江苏，30)
| A．so that | B．no matter how |
| C．as long as | D．except that |
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 |