男性，59岁，确诊肺结核并住院治疗1个月，上厕所解大便后出现胸闷、气憋、口唇和指甲发

所谓"刚体作平动"，指的是刚体运动时有下列中的哪种性质？（）

A.刚体内有一直线始终保持与它原来的位置平行

B.刚体内有无数条直线始终保持与它原来的位置平行

C.刚体内任一直线始终保持与它原来的位置平行

D.只在某瞬时，刚体内各点的速度相同

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.

“输入掩码”用于设定控件的输入格式，对什么数据有效

A．数字型

B．货币型

C．日期型

D．备注型

据调查结果显示．2011年上半年31个省份城乡居民收入增速全部高于CPI。以北京为例，上半年．城镇居民人均可支配收入比上年同期增长10.1%，农村居民人均现金收入比上年同期增长12.4%．而同期CPI涨幅为5.4%。但很多人却表示自己的月收入没有什么增加．而对物价的上涨却“深有体会”。
以下哪项如果为真．最能解释题干现象

A．上半年有一小部分人的收入增幅较大．带动了居民收入的整体增速
B．上半年食品类价格上涨11.8%．非食品类价格上涨2.7%
C．各省区市的数据来源为抽样统计．不可能覆盖到所有人。因此数据不可能保证100%准确
D．统计数据中的收入增速包括年终奖、单位福利等工资以外的其他收入

2012年3月，有甲乙丙丁四架飞机以同样的速度沿所在纬线自西向东飞行（如图）。据此回答小题

在乙飞机上空俯视地球绘制的地球运动的投影图正确的是（）

A.A

B.B

C.C

D.D