The worried general was looking at the map when the idea of the enemy’s attack might be launched ______dawn ______ his mind.
| A．at; crossed | B．at; to cross |
| C．before; came across | D．after; went over |
He must have sensed that I ______ him. He suddenly glanced at me and said quietly, “Why are you staring at me like that?”
| A．would look at | B．looked at |
| C．was looking at | D．am looking at |
It was not until the end of the trip ______ I realized what a good feeling it was to have helped someone in trouble.
| A．as | B．that | C．where | D．when |
As a Chinese saying goes,a mountain ______ be too high or an ocean too deep. Therefore, there is no end to our self-improvement.
| A．shall never | B．will ever | C．can never | D．must ever |
Sometimes I act as a listening ear for fellow students ______ what is bothering them.
| A．to talk over | B．talked about |
| C．talk about | D．having talked over |
An increased concentration of carbon dioxide and certain other gases in the Earth’s atmosphere ______ global warming.
| A．contributing to | B．contribute to |
| C．contributes to | D．to contribute to |