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问题 选择题

中南半岛的气候类型主要是（　　）

A．热带草原气候

B．热带季风气候

C．热带雨林气候

D．亚热带季风气候

答案

中南半岛地处低纬度地区，主要的气候类型是热带季风气候，其特点是终年高温，降水分旱雨两季．

故选：B．

单项选择题 A1型题

病原体侵入人体后，仅引起机体发生特异性的免疫应答，而不引起或只引起轻微的组织损伤，临床上不显出任何症状、体征与生化改变，只能通过免疫学检查才能发现。此种表现属于（）

A.病原体被清除

B.隐性感染

C.显性感染

D.病原携带状态

E.潜伏性感染
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填空题

The central problem of economics is to satisfy the people’s and nation’s wants. The problem we are faced with is that our (1) , here identified as money, are (2) . The only way we can resolve our (3) is to make choices. After looking at our resources, we must examine our list of (4) and identify the things we need (5) , those we can postpone, and (6) we cannot afford. As individuals, we face the central problem involved in economics — deciding just how to allocate our limited resources to provide ourselves with the greatest (7) of our wants.
Nations face the same problem. As a country’s population (8) , the need for more goods and services grows (9) . Resources necessary to production may increase, but there are (10) enough resources to satisfy the total desires of a (11) . Whether the budget meeting is taking place in the family living-room, in the conference room of the corporation (12) of directors, or in the chamber of the House of Representatives in Washington, the basic problem still exists. We need to find (13) of allocating limited resources in order to satisfy unlimited wants.
A short time ago, economists divided goods into two categories, free and economic. The former, like air and water, were in (14) abundance that economists had no concern about (15) of scarcity and what to do about it. Today many of these "free goods" are in (16) very expensive to use. Pollution has made clean air and water expensive for producers who have to filter their waste products, for consumers who ultimately pay for the producers’ extra costs, and (17) tax-payers who pay for the government’s involvement in cleaning the environment.
In the 1990s, almost all goods are (18) . Only by effort and money can they be (19) in the form people wish.
Meeting the needs of people and the demands from resources available leads to the basic activity of production. In trying to (20) unlimited wants from limited economic goods, production leads to new problems in economics.
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