The earth could be younger and took more than three times longer to form than _______ thought, according to a new study.
| A．favorably | B．deliberately | C．practically | D．previously |
The professor can hardly find sufficient grounds his argument in favor of the theory.
| A．which to base on |
| B．on which he bases |
| C．to base on which |
| D．which to be based |
—Sorry，my dog frightened your daughter.
—Forget it！________.
| A．She deserved it |
| B．Every dog has its day |
| C．Bad luck comes three |
| D．Animals will be animals |
The teacher stressed again that the students should not________any important details while retelling the story.
| A．bring out |
| B．let out |
| C．leave out |
| D．make out |
I will put the book________you placed it and make a mark at the place________I put it.
| A．where；at which |
| B．at which；at which |
| C．where；which |
| D．at which；where |
—Shall we have our picnic tomorrow?
—________ it doesn’t rain.
| A．Until |
| B．While |
| C．Once |
| D．If |