She is so ___ that no one can ever persuade her．
| A．reliable | B．stubborn | C．artificial | D．intelligent |
, a good idea occurred to him.
| A．After a while |
| B．For a while |
| C．At the while |
| D．A great while |
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 |
Two lawyers have donated $50,000 to ________ our school's campaign "Help the Needy", whichwas started by our former headmaster three years ago.
| A．sponsor |
| B．launch |
| C．organize |
| D．plan |
The experiment shows that proper amounts of exercise, if regularly, can improve our health.
| A．being carried out |
| B．carrying out |
| C．carried out |
| D．to carry out |
This coastal area a national wildlife reserve last year.
| A．was named |
| B．named |
| C．is named |
| D．names |