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问题 单项选择题

患者陈某有风湿性关节炎病史，心脏听诊主动脉瓣区有舒张期杂音，X线胸片示左心室扩大，用彩色多普勒技术应有的表现是

A．左心室在收缩期有血流射入右心室

B．显示有血流从主动脉瓣口在舒张期流向左心室

C．收缩期有血流从右心室流入右心室

D．左心室在收缩期无血流射入主动脉

E．收缩期有血流从左房流入左心室

答案

参考答案：B

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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单项选择题

我国实行宗教信仰政策的含义是（）。

A.我国公民享有宗教信仰自由

B.宗教组织可以向社会宣传有神论

C.国家鼓励群众的信教活动

D.宗教的消极作用已经消失
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