Bird flu , a contagious disease of animals , is believed ____ by viruses that normally infect only birds and less commonly pigs , and rarely humans .
| A．caused | B．being caused | C．to be caused | D．to have caused |
27.—It’s cloudy outside. Please take an umbrella.
—__________.
| A．Yes, take it easy | B．Well, it just depends. |
| C．Ok, just in case | D．All right, you’re welcome |
26. There was no doubt ____ it was in the supermarket _____ I lost my wallet yesterday.
| A．whether, whether | B．that, that | C．that, whether | D．whether, that |
25. Time _____, I will go there with you.
| A．permits | B．permitted | C．will permit | D．Permitting |
24. _____ any biscuits that morning, we had nothing to eat.
| A．Not baking | B．Not having baked |
| C．Not being baked | D．Not having been baked |
23.— It’s a long time _____ I saw you last.
— Yes, and what a pity! It will be a long time ____ we see each other again.
| A．before, since | B．since, before | C．when, when | D．since, when |