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The Internet is not an ordinary encyclopedia, i. e, an organized knowledge database. The Internet is more like a disorganized database to which everyone can contribute. Because of the diverse and widespread information when one needs it, there is a need to bring some sort of organization to the Internet community. Today, there are web directories and search engine as two of the most useful mechanisms responsible for bringing order to the Internet.Web directories organize links to many places on the Internet where information about a specific topic can be found. Web directories can have a general or topic specific focus and are usually organized into several categories based on the topic specific focus. Web directories are good sources of information if they are well-maintained with regular updates. They are usually maintained better by human software.Search engines are yet another tool that helps you find information on the Internet. There are many search engines on the Internet but the biggest and the most popular are Google, AOL Netscape, Lycos and MSN.Search engines, however, are different from web directories. They do not categorize links to web places like web directories do but they allow users to "search the Internet" using specific search terms. However, it should be noted that what is really being searched at the moment you submit your inquiry (in the form of a search term) is, in fact, a database. There databases are constantly updated and upgraded with so called "search engine spiders" which search the Internet all the time looking for new and recently updated websites. The best title of the passage is likely to be ______.
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Social change is more likely to occur in societies where there is a mixture of different kinds of people than in societies where people are similar in many ways. The simple reason for this is that there are more different ways of looking at things present in the first kind of society. There are more ideas, more disagreements in interest, and more groups and organizations with different beliefs. In addition, there is usually a greater worldly interest and greater tolerance in mixed societies. All these factors tend to promote social change by opening more areas of life to decision. In a society where people are quite similar in many ways, there are fewer occasions for people to see the need or the opportunity for change because everything seems to be the same. And although conditions may not be satisfactory, they are at least customary and undisputed.Within a society, social change is also likely to occur more frequently and more readily in the material aspects of the culture than in the non-material, for example, in technology rather than in values; in what has been learned later in life rather than what was learned early; in the less basic and less emotional aspects of society than in their opposites; in the simple elements rather than in the complex ones; in form rather than in substance; and in elements that are acceptable to the culture rather than in strange elements.Furthermore, social change is easier if it is gradual. For example, it comes more readily in human relation on a continuous scale rather than one with sharp dichotomies (一分为二). This is one reason why change has not come more quickly to Black American as compared to other American minorities, because of the sharp difference in "appearance between them and their white counterparts". In the first paragraph "greater tolerance" probably refers to ______.
Since the beginning of history, man has been fascinated by the idea of living for ever, of winning the fight against death and disease. So far, this has only remained a dream, though a very powerful one. Many people have wondered whether it would be possible to find a way to preserve human bodies, and what would be the best way to preserve human bodies.It has long been known that meat or fruit can be kept fresh for long periods by freezing; in ancient China, for example, food was stored with ice to keep it fresh. This method could also be useful for preserving humans, and in fact many people have explored this possibility.However, most living beings that exist under warm conditions die when frozen. This is because of the harmful effects of freezing ice crystals (晶体), which are not only larger than the volume of the water originally in the cells, but also form sharp cutting shapes that harm the cells.In the 1940s, Dr. B.J. Luyet and a group of scientists in England were working on the problem of freezing cells without damaging them. Since the harm caused by ice crystals was the main cause of the damage, Luyet suggested removing some or all of the water from the cells before freezing them.Using living cells from chicken, Luyet and his assistants discovered that they could partly dry the chicken cells, using a mixture of the white part of an egg and glycerin (丙三醇), a clear, thick liquid made chiefly from fats and oils. Some success was obtained. The chicken cells were dried, frozen for a period of time, and then carefully unfrozen. Almost all the cells recovered when they reached normal temperatures.Since then, the cooling of whole animals to a temperature very much below freezing point for later unfreezing has become more of a possibility, and the glycerin method would probably be used to accomplish this. When this can be done completely and successfully, science will have moved much closer to its aim of freezing and storing incurable patients until the day they can be cured. Glycerin can be used ______.
Since the beginning of history, man has been fascinated by the idea of living for ever, of winning the fight against death and disease. So far, this has only remained a dream, though a very powerful one. Many people have wondered whether it would be possible to find a way to preserve human bodies, and what would be the best way to preserve human bodies.It has long been known that meat or fruit can be kept fresh for long periods by freezing; in ancient China, for example, food was stored with ice to keep it fresh. This method could also be useful for preserving humans, and in fact many people have explored this possibility.However, most living beings that exist under warm conditions die when frozen. This is because of the harmful effects of freezing ice crystals (晶体), which are not only larger than the volume of the water originally in the cells, but also form sharp cutting shapes that harm the cells.In the 1940s, Dr. B.J. Luyet and a group of scientists in England were working on the problem of freezing cells without damaging them. Since the harm caused by ice crystals was the main cause of the damage, Luyet suggested removing some or all of the water from the cells before freezing them.Using living cells from chicken, Luyet and his assistants discovered that they could partly dry the chicken cells, using a mixture of the white part of an egg and glycerin (丙三醇), a clear, thick liquid made chiefly from fats and oils. Some success was obtained. The chicken cells were dried, frozen for a period of time, and then carefully unfrozen. Almost all the cells recovered when they reached normal temperatures.Since then, the cooling of whole animals to a temperature very much below freezing point for later unfreezing has become more of a possibility, and the glycerin method would probably be used to accomplish this. When this can be done completely and successfully, science will have moved much closer to its aim of freezing and storing incurable patients until the day they can be cured. According to the passage, freezing is ______.
My husband and I took off to Bafflo to help Mum move out of her apartment in Bafflo, New York. The plan was to pack everything into her van so that she could drive around visiting families and friends for the next ten days before heading back to her home in Florida.After dinner we headed back onto the road, Mum in the van with us behind in our rental car. The next moment changed everything: a deer jumped out in front of the van and Mum ran right into it. There was nothing she could do. It was awful. Police arrived. Calls were placed. The tow truck arrived. We moved essentials into our car and made plans to get Morn to a hotel near the garage. Everything fell into place in a mechanical way. And I worried about Mum, of course, but what troubled me most was the deer because it wasn"t dead. When the police officer shone his light around the accident scene, two beautiful brown eyes were frozen in the beam of light. It was lying down on someone"s front lawn, still, shocked, but very alive.I couldn"t even look at it. I asked the police officer if he could shoot it, but because it was a residential area, other methods were needed. The officers felt its legs to confirm that they were not broken, and gently pushed it, hoping that the push would inspire the poor animal to turn. But it sat there, probably suffering from internal injuries. And that caused me to feel a deep and powerful sadness. If that was a person lying in the ditch, there would be ambulances and doctors busily working to relieve pain and save life. But no, it was an animal, and there is no justice for animals. The author was most concerned that ______.
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