The boy was saved because the doctor arrived there _____ it was too late.
| A．before | B．since | C．or | D．while |
The girl got into ________ panic when she heard ________ frightening news.
| A．a; the | B．a; a |
| C．the; the | D．the; a |
—Do you know what EU stands for, Tommy?
—Sure.It stands for the European Union，________ European political and economic organization that encourages trade and friendship between ________ countries that are members.
| A．an; the | B．a; the |
| C．the; / | D．an; / |
It is announced that________$20,000 reward will be offered for ________ return of the stolen sculpture.
| A．a; the | B．/; the |
| C．a; a | D．/; a |
The most important thing to keep in ________ mind when dealing with________ emergency is to stay calm.
| A．/; the | B．the; an |
| C．the; the | D．/; an |
We can never expect ________ bluer sky unless we create________ less polluted world.
| A．a; a | B．a; the |
| C．the; a | D．the; the |