According to the United Nations, an aging society refers to one ____ 10 percent or more of the population is over 60, or 7 percent or more is over 65.
Harry telephoned to the airport to______ whether Flight 24 for San Francisco is departing on time.
—Will you be ______ this evening, Mary?—That depends. I am afraid I will be with my manager discussing a plan.
Children who are spoiled by their parents are more _____ than others —they are more likely to fight with their fellows for toys and candies.
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.
The school, more than 90 percent of whose graduates are usually admitted into key universities, enjoys an excellent _______.