The experiment has_________ the possibility of the existence of any life on that planet, but it does not mean there is no life on other planets.
| A．found out | B．pointed out | C．ruled out | D．carried out |
It was Tom and his friends that________for the serious accidents.
| A．were to be blamed | B．was to be blamed | C．were to blame | D．was to blame |
He was reading a very interesting story, completely_______himself in the story.
| A．lost | B．being lost | C．to be lost | D．losing |
Whoever invented _______wheel is believed to have made ______most useful invention in _______history.
| A．a; the; / | B．the; the; / | C．the; a; / | D．a; a; the |
The importance of saving gas_______be stressed too much. Automobiles use up some 70 billion gallons of gas a year.
| A．can’t | B．mustn’t | C．shouldn’t | D．may not |
Every day the boy, together with his classmates,_______to go to the sports ground and______football, _________themselves.
| A．are noticed; play; enjoying | B．is noticed; plays; enjoying |
| C．are noticed; plays; enjoys | D．is noticed; play; enjoying |