_______ there are many different types of food, some animals spend their lives eating only one type.
| A．Since | B．Unless | C．Once | D．While |
After that, he knew he could __________ any emergency by doing what he could to the best of his ability.
| A．get away with |
| B．get on with |
| C．get through |
| D．get across |
Never before __________ seen anybody who can play tennis as well as Robert.
| A．had she |
| B．she had |
| C．has she |
| D．she has |
Only with the greatest of luck __________ to escape from the rising flood waters.
| A．managed she |
| B．she managed |
| C．did she manage |
| D．she did manage |
The headmaster will not permit the change in the course, nor __________ it a thought.
| A．does he even give |
| B．he even gives |
| C．will he even give |
| D．he will even give |
(2012·辽宁) Not until he retired from teaching three years ago __________ having a holiday abroad.
| A．he had considered |
| B．had he considered |
| C．he considered |
| D．did he consider |