When I was twenty, I had to ___ before graduation and work in a clothes shop to help support my family.
| A．drop out | B．come out | C．leave out | D．stay out |
Mike, whose ambition is to become a network engineer, was always ______from other boys by his programming ability.
| A．prevented | B．separated | C．benefited | D．distinguished |
Harry telephoned to the airport to______ whether Flight 24 for San Francisco is departing on time.
| A．prove | B．ensure | C．confirm | D．identify |
—Will you be ______ this evening, Mary?
—That depends. I am afraid I will be with my manager discussing a plan.
| A．demanding | B．suitable | C．available | D．efficient |
Children who are spoiled by their parents are more _____ than others —they are more likely to fight with their fellows for toys and candies.
| A．pessimistic | B．sensitive | C．aggressive | D．Punctual |
Some people say that Mars should be protected as a wildlife reserve where we do everything possible to avoid pollution, on the _______ that life could exist on it.
| A．assumption | B．arrangement | C．assistance | D．appointment |