已知z1=4-4sinθ+i，其中i为虚数单位，θ∈R．（1）求|z1|的取值范

在超市里选购液态乳制品时，鉴别是纯牛奶还是奶饮料，主要是依据下列那两种物质进行（）

A.乳蛋白质含量

B.乳脂肪含量

C.乳糖含量

D.维生素含量

E.干物质含量

患者男性，69岁，既往有高血压病史30年，平素血压控制不详。患者午睡后出现左侧肢体瘫痪2小时就诊。查体：血压200／120mmHg，嗜睡，左侧同向性偏盲，左侧瞳孔：右侧瞳孔=1．5mm：2．0mm，光反射存在，左侧眼裂变小，双眼球向右侧凝视，左侧鼻唇沟变浅，伸舌左偏，左侧肢体肌力0级，肌张力低，左侧肢体痛觉减退，左下肢巴氏征阳性。

溶栓并发症有哪些（）

A.梗死灶继发出血

B.肺部感染

C.血糖增高

D.致命的再灌注损伤和脑水肿

E.上消化道出血

F.再闭塞

影响散热损失的因素有哪些？

（）仅能配置在HGB框，每个ONU配置一块

A.ALC板

B.PV8板

C.CDI板

D.TSS板

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.