[简答题]Most of the world’s victims of AIDS live—and, at an alarming rate, die—in Africa. The number of people living with AIDS in Africa was estimated at 26.6 million in late 2003. New figures to be published by the United Nations Joint Program on AIDS (UNAIDS), the special UN agency set up to deal with the pandemic, will probably confirm its continued spread in Africa, but they will also show whether the rate of spread is constant, increasing or falling. AIDS is most prevalent in Eastern and Southern Africa, with South Africa, Zimbabwe and Kenya having the greatest numbers of sufferers; other countries severely affected include Botswana and Zambia. AIDS was raging in Eastern Africa—where it was called "slim", after the appearance of victims wasting away—within a few years after its emergence was established in the world in 1981. One theory of the origin of the virus and syndrome suggests that they started in the eastern Congo basin; however, the conflicting theories about the origin of A

[单项选择]Most Americans live according to time segments laid out in engagement calendars.（　）
A. Most Americans carry a calendar with them wherever they go.
B. Most Americans have a calendar to write their engagements on.
C. Most Americans plan their time carefully and follow a strict schedule.
D. Most Americans only meet people who have made an appointment with them.

[单项选择]

The fact that most Americans live in urban areas does not mean that they reside in the center of large cities. In fact, more Americans live in the suburbs of large metropolitan areas than in the cities themselves.
The Bureau of the Census regards any area with more than 2,500 people as an urban area, and does not consider boundaries of cities and suburbs.
According to the Bureau, the political boundaries are less significant than the social and economic relationships and the transportation and communication systems that integrate a locale. The term used by the Bureau for an integrated metropolis is an MSA, which stands for Metropolitan Statistical Area. In general, an MSA is any area that contains a city and its surrounding suburbs and has a total population of 50,000 or more.
At the present time, the Bureau reports more than 280 MSAs, which together account for 75 percent of the U.S. population. In addition, the Bureau recognizes 18 megapolises, that is,
A. fill
B. decide
C. occupy
D. live