螺纹联结为了达到可靠而紧固的目的，必须保证螺纹副具有一定的（）。A.摩擦力矩 B.拧

The American economic system is organized around a basically private-enterprise, market-oriented economy in which consumers largely determine what shall be produced by spending their money in the marketplace for those goods and services that they want most. Private businessmen, striving to make profits, produce these goods and services in competition with other businessmen; and the profit motive, operating under competitive pressures, largely determines how these goods and services are produced. (47)Thus, in the American economic system it is the demand of individual consumers, coupled with the desire of businessmen to maximize profits and the desire of individuals to maximize their incomes that together determine what shall be produced and how resources are used to produce it.
(48)An important factor in a market-oriented economy is the mechanism by which consumer demands can be expressed and responded to by producers. In the American economy, this mechanism is provided by a price system, a process in which prices rise and fall in response to relative demands of consumers and supplies offered by seller-producers. If the product is in short supply relative to the demand, the price will be bid up and some consumers will be eliminated from the market. (49)If, on the other hand, producing more of a commodity results in reducing its cost, this will tend to increase the supply offered by seller-producers, which in turn will lower the price and permit more consumers to buy the product. Thus, price is the regulating mechanism in the American economic system.
The important factor in a private-enterprise economy is that individuals are allowed to own productive resources (private property), and they are permitted to hire labor, gain control over natural resources, and produce goods and services for sale at a profit. (50)In the American economy, the concept of private property embraces not only the ownership of productive resources but also certain rights, including the right to determine the price of a product or to make a free contract with another private individual.

将适量的下列物质溶解于水的过程中，会使溶液的温度显著降低的是

A．浓硫酸

B．硝酸铵

C．火碱

D．蔗糖

肝转移癌的"靶征"中，其高信号的外晕环与下列哪项有关（）

A.纤维结缔组织形成

B.细胞的凝固性坏死

C.脂肪浸润

D.生长活跃的肿瘤细胞

E.肿瘤的液化囊变

在DOS环境下，禁用文件名是 ( )

A．COM

B．LPr3

C．LFT4

D．串口

阅读下列材料

材料一：在西方世界日益关注中国的过程中，《时代》周刊是最典型的代表。毛 * * 和邓 * * 曾分别于1949年和1979年成为《时代》周刊的封面人物。

材料二：1949年，毛 * * 用同心圆、原子结构或者洋葱作比喻，给权力的构成下了定义。圆的核心是由工人阶级组成，通过代表它的党行使领导权。紧靠核心的是农民，他们构成了无产阶级最可靠的同盟军。接着是小资产阶级，他们主要是追随者。至于民族资产阶级……

——[美]费正清《剑桥中华人民共和国史》

材料三：（英国）1832年第一次国会选举制度改革，可以被看作是适应工业革命大潮的第一步。到19世纪三四十年代工业革命完成后，各项改革更是接踵而来，一发不可止歇。这些改革，择其要者大致有：40年代实行自由贸易、1846年废除《谷物条例》、1867年第二次国会选举制度改革、70年代开始的教育改革、1884年第三次国会选举制度改革、19世纪末劳动立法等社会改革。

——刘宗绪《历史学科专题讲座》

请回答：

概述“光荣革命”后，英国是怎样推进民主的？如何认识英国的民主？