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What is of greatest concern is the sudden rise in the number of workers and students who now admit to trying cocaine, a dangerously addictive and very costly drug. Recent surveys show that this drug has spread from the entertainment world to small town high schools where more than 17% of the seniors say they tried cocaine. Because there's little agreement about the causes of this surge in drug abuse, there's even less agreement about what should be done to solve it.

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Some Knowledge in Physics
1．The sun is the source of most of heat known to us. As a direct source of heat, the sun maintains life upon this planet, 150,000,000 kilometers distant. It is also an indirect source of heat. Since the earth is derived from the sun, it is to the latter that we must trace some of the earth's internal heat that reveals itself through volcanoes, geysers (喷泉),and hot springs.
2．An insect is not afraid of gravity, but it is in deadly fear of another force of nature. This force is called surface tension (张力). A man coming out of a bath carries with him a film of water a bout one fiftieth of an inch in thickness. This weighs about a pound. A wet mouse has to carry its own weight in water. A wet fly has to lift many times its own weight, and, as everyone knows, a fly once wetted by water or any other liquid is in a very serious position indeed. An insect going for a drink is in as great danger as a man leaning over the edge of a cliff in search of food. If it once falls into the grip of the surface tension of the water--that is to say, gets wet--it is likely to remain so until it drowns. A few insects contrive to be unwettable; the majority keep away from their drink by means of long proboscis (喙).
3．When the temperature of a liquid is raised enough, the liquid boils. This means that bubbles of vapor, containing millions of molecules form. below the surface. In order for such bubbles to be produced, the pressure of the vapor inside them must be equal to the pressure of the air upon the surface of the liquid. If the air pressure is greater, the bubble will collapse. The boiling point of a liquid, then, is the temperature at which the vapor pressure of the liquid is equal to the atmospheric pressure upon the liquid at the surface.
4．Solids also expand with increase in temperature and contract when cooled. But they do not behave quite so uniformly (相同地) in this respect as liquids and gases do, particularly in the case of wide variations, in temperature. Most solids expand or contract by a definite amount for every degree of the temperature that rises or falls. The amount by which no substance expands and contracts for one degree is not usually the same as that for a different substance. Thus, for a given rise in temperature, a piece of brass expands a little more than a piece of copper and much more than a piece of steel of the same size.
5．Electric trains have many advantages over those drawn by steam engines. There is no smoke to soil the passengers' clothes and the cushions in the train. Because they carry on heavy loads of coal and water, these trains can start and stop with less waste of power. In a station they are silent: there's no steam to produce noise to deafen the passengers.
A Insects and Surface Tension
B Expansion and Contraction
C Temperature of Boiling Point of Liquids
D Principals in physics
E Advantages of Electric Trains
F The Solar Energy
Paragraph 2 ______

Our theories about human disease are the product of current fashion 【M1】
than we would like to admit. But just as the moment influences the hemline
and the automobile fender, so too a type of intellectual currency 【M2】
affect our understanding of how illness happens. Much of
the 20th century is spent in pursuit of external causes of 【M3】
disease - cigarettes, fatty foods, tick bites. Rather like the hero in an old western,
medicine’s work was to track down the bad guys, round them up 【M4】
and squish them before a real commotion. Antibiotics, vaccines,
heart pills - these were our weapons in the epic battle between us and them, good versus evil.
More recently, although, we have cast our gaze inward, mesmerized by 【M5】
our own adorable DNA. Just last decade, after 40 years of intense flirtation,
this relationship was consummated as we cloned the entire human genome.
Promise of improved health and longevity soon followed, 【M6】
as we had apparently found our way to the bedrock truths that underlie all illness.
But with this orgy of molecular self-admiration
has come a fundamental shift of thinking 【M7】
about human disease. We have moved from our long-hold premise 【M8】
which the outside world (too much ice cream and flesh-eating bacteria) threatens【M9】
us to a belief that the trouble rises from something much closer 【M10】
to home - our own double-crossing genes.
【M1】

请认真阅读下列有关Linux操作系统环境下配置成一台DNS服务器的说明信息，然后根据要求回答问题1至问题5。
【说明】
一台装有Linux操作系统的电脑，IP地址是“192.168.0.39'’，主机名是dnserver。现在要在这台电脑上配置成一台DNS服务器，让它负责abc.net这个域的解析工作。
整个过程需要配置以下几个配置文件。
位于/etc目录下的系统文件如下：
/etc/hosts
/etc/host．conf
/etc/resolv．conf
/ete/named．conf
位于/var/named目录下的资源记录文件如下：
/var/named/named.abc.net
/var/named/named.abc.net.rev
资源记录文件位于/var/named目录下。这个目录是在以上的(1)文件中定义的。

______是一个Excel文件，其中可以含有一个或多个工作表。