While other scientists are keeping____eye on changes in the H5N1 bird flu strain, the scientists in England are working on vaccines, in case it becomes highly infectious in ____humans.
| A．a , / | B．an, / | C．the, an | D．an, the |
________ true events, the film follows the life of Ali, a world famous boxer in the US.
| A．Being based on | B．Basing on |
| C．Based on | D．Having based on |
The building, _________ roof was damaged in the big fire, is actually a small hospital.
| A．where | B．whose | C．which | D．that |
Now that the weather is so bad, the sports meet ___________ .
| A．is to put off | B．is put off | C．is to be put off | D．will put off |
Those children don’t have to ____________ learn , for they always work hard voluntarily.
| A．make to | B．be made | C．make them | D．be made to |
Can you think of a new situation _________ this phrase can be used?
| A．that | B．for which | C．where | D．when |