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随着人类对火星的了解越来越多，许多科学家，尤其是美国宇航局的研究专家都已经开始探索人类未来移民火星的可行性。对于将火星改造成“绿色星球“的惊人设想，许多科学家都认为至少需要2万年到10万年左右的时间，但美国非赢利性科研组织“火星协会”创始人、美国工程师罗伯特·祖柏林却认为，改造火星的过程大约只要1000年时间就可以完成。 根据上文推断，作者接下来最可能讲述的内容是( )。
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TEXT A Petroleum products, such as gasoline, kerosene, home heating oil, residual fuel oil, and lubricating oils, come from one source - crude oil found below the earth’s surface, as well as under large bodies of water, from a few hundred feet below the surface to as deep as 25,000 feet into the earth’s interior. Sometimes crude oil is secured by drilling a hole through the earth, but more dry holes are drilled than those producing oil. Pressure at the source or pumping forces crude oil to the surface. Crude oil wells flow at varying rates, from ten to thousands of barrels per hour. Petroleum products are always measured 42-gallon barrels. Petroleum products vary greatly in physical appearance: thin, thick, transparent or opaque, but regardless, their chemical composition is made up of two elements: carbon and hydrogen, which form compounds called hydrocarbons. Other chemical elements found in union with the hydrocarbons are few and are classified as impurities. Trace elements are also found, but these are of such minute quantifies that they are disregarded. The combination of carbon and hydrogen forms many thousands of compounds which are possible because of the various positions and joinings of these two atoms in the hydrocarbon molecule. The various petroleum products are refined from the crude oil by heating and condensing the vapors. These products are the so-called light oils, such as gasoline, kerosene, and distillate oil. The residue remaining after the light oils are distilled is known as heavy or residual fuel oil and is used mostly for burning under boilers. Additional complicated terming processes rear~ range the chemical structure of the hydrocarbons to produce other products, some of which are used to upgrade and increase the octane rating of various types of gasoline. Which of the following is NOT listed as a light oil
TEXT D Federal officials should consider reopening public access to about three dozen Web sites withdrawn from the Internet after the Sept. 11, 2001, attacks, a government-financed study says, because the sites pose little or no risk to homeland security. The Rand Corp. said the overwhelming majority of federal Web sites that reveal information about airports, power plants, military bases and other potential terrorist targets need not be censored because similar or better information is easily available elsewhere. Rand identified four Web pages that might merit the restrictions imposed after the attacks. "It’s a good time to take a closer look at the choices that they made at the time," said John Baker, principal author of the study, which was funded by the National Geospatial-Intelligence Agency, the government’s intelligence mapping agency. Advocates of open government said the report shows the Bush administration acted rashly after the suicide attacks when it scrubbed numerous government Web sites. About how many websites have been withdrawn from the internet after the Sept. 11, 2001 in America
近年来，不少国家纷纷实施“人与生物圈计划”，目的就是为了寻求同一个答案。为什么人类在享受自己获得和创造的财富时，会不时受到大自然种种惩罚因为人类在土壤侵蚀、沙漠化、滥伐森林、越来越多的物种灭绝、环境污染等所导致的生态系统退化中，逐步意识到自身还没有真正揭开人与生物圈之问的秘密。 这段话中“秘密”一词具体指的是( )。
TEXT C When companies do business overseas, they come in contact with people from different cultures. These individuals often speak a different language and have their own particular custom and manners. These differences can create problems. For example, in France, business meetings begin promptly at the designated time and everyone is expected to be there. Foreign business people who are tardy are often left outside to cool their heels as a means of letting them know the importance of promptness. Unless one is aware of such expected behaviors he may end up insulting the people with whom he hopes to establish trade relations. A second traditional problem is that of monetary conversions. For example, if a transaction is conducted with Russia, payment may be made in rubles. Of course, this currency is of little value to the American firm. It is, therefore, necessary to convert the foreign currency to American dollars. How much are these Russian rubles worth in terms of dollars This conversion rate is determined by every market, where the currencies of countries are bought and sold. Thus there is an established rate, although it will often fluctuate from day to day. For example, the ruble may be worth ’0.75 on Monday and ’0.72 on Tuesday because of an announced wheat shortage in Russia. In addition, there is the dilemma associated with converting at ’0.72. Some financial institutions may be unwilling to pay this price, feeling that the ruble will sink much lower over the next week. As a result, conversion may finally come at ’0.69. These "losses" must be accepted by the company as one of the costs of doing business overseas. A third unique problem is trade barriers. For one reason or another, all countries impose trade barriers on certain goods crossing their borders. Some trade barriers are directly related to exports. For example, the United States permits strategic military material to be shipped abroad only after government permission has been obtained. Most trade barriers, however, are designed to restrict import. Two of the most common import barriers are quotas and tariffs. In France, tardy business people ______.
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