________ caused the accident is still a complete mystery.
| A．What | B．That | C．How | D．Where |
--Mom. I’m so tired. I can’t walk any further.
---______, my dear. You can make it.
| A．Come on | B．No worry | C．That’s impossible | D．No problem |
I don’t think you should mention it at the beginning of the story, or it may ____ the shocking ending.
| A．give out | B．give away | C．give up | D．give off |
To tell the truth, I would rather that I ____ the pain instead of you. You don’t know how worried I was.
| A．took | B．had taken | C．have taken | D．should have taken |
____ of the land in that district ____ covered with trees and grass.
| A．One half; are | B．Two seventh; is |
| C．A quarter; is | D．Two thirds; are |
People have lots of problems living in the central Australian desert, ____ the lack of water is the most serious one.
| A．of which | B．which | C．for which | D．where |