She opened her eyes with a start and was about to cry out _____ she heard her father urgently telling her to keep quiet.
| A．while |
| B．when |
| C．before |
| D．after |
The ___ bear was cornered in the forest __ hunters were closing for the kill.
| A．frightened; where | B．frightening; when | C．frightened; as | D．frightening; before |
The Meglev Train travels in a vacuum between two magnets, ___ no pollution is caused and less energy is consumed.
| A．where | B．which | C．when | D．therefore |
Do be careful with what you are to say. If you ___, you will leave a bad impression.
| A．don’t | B．aren’t | C．won’t | D．can’t |
Come on! The man in charge of the job ___ you have to explain everything is waiting.
| A．who | B．about which | C．to whom | D．where |
I had no one ___ me, for I could deal with it all by myself.
| A．to help | B．help | C．helped | D．helping |