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2021-03-26 16:39:17
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2021-03-26 16:36:30
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题型描述: 阅读理解 Space is a dangerous place, not only because of meteors (流星 ) but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through, and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation but their spacesuits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage. Radiation is the greatest known danger to explorers in space. The unit of radiation is called “rem”. Scientists have reason to think that a man can put up with far more radiation than 0.1 rem without being damaged; the figure of 60 reins has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage — a person may feel perfectly well, but the cells of his or her sex organ may be damaged, and this will no be discovered until the birth of deformed children or even grandchildren. Missions of the Apollo flights have had to cross belts of high amount of rems. So far, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but no really effective ones have been found so far.
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题型描述: 阅读理解 In the early days of the internet, many people worried that as people in the rich world embraced new computing and communications technologies, people in the poor world would be left stranded on the wrong side of a “digital divide.” Yet the debate over the digital divide is founded on a myth — hat plugging poor countries into the internet will help them to become rich rapidly. This is highly unlikely, because the digital divide is not a problem in itself, but a symptom of deeper, more important divides: of income, development and literacy. Fewer people in poor countries than in rich ones own computers and have access to the internet simply because they are too poor, are illiterate, or have other more immediate concerns, such as food, health care and security. So even if it were possible to wave a magic wand and cause a computer to appear in every household on earth, it would not achieve very much: a computer is not useful if you have no food or electricity and cannot read. Yet such Wand-waving — through the construction of specific local infrastructure projects such as rural telecenters — is just the sort of thing for which the UN's new fund is intended. This sort of thing is the wrong way to go about addressing the inequality in access to digital technologies: it is treating the symptoms, rather than the underlying causes. The benefits of building rural computing centers, for example, are unclear. Rather than trying to close the divide for the sake of it, the more sensible goal is to determine how best to use technology to promote bottom-up development. And the answer to that question turns out to be remarkably clear: by promoting the spread not of PCs and the Internet, but of mobile phones.
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2021-01-14 23:51:51
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2021-01-14 23:51:51
