— Why do you do volunteer work in the North-West?
— I_______ to improve the lives of the children there through my efforts.
| A．was trying | B．have tried | C．am trying | D．tried |
Martin was_____ to win the 100-meter race, but he fell to the ground and missed the chance.
| A．likely | B．possible | C．probable | D．maybe |
The roads have ______ because of people’s dependence on cars.
| A．jammed | B．been jamming | C．to jam | D．been jammed |
Green organizations are trying to save rain forests that have been _____ by farmers.
| A．created | B．ruined | C．threatened | D．protected |
After dinner he gave Mr Richard ______ ride to ______ Great Wall.
| A．the; a | B．a; the | C．不填; a | D．不填; the |
______ I admit that all these problems are difficult, I don’t agree that they can’t be solved.
| A．Unless | B．While | C．Until | D．Since |