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If good intentions and good ideas were all it took to save the deteriorating atmosphere, the planet"s fragile layer of air would be as good as fixed. The two great dangers threatening the blanket of gases that nurtures and protects life on earth—global warming and the thinning ozone layer—have been identified. Better yet, scientists and policymakers have come up with effective though expensive countermeasures. But that doesn"t mean these problems are anywhere close to being solved. The stratospheric ozone layer, for example, is still getting thinner, despite the 1987 international agreement known as the Montreal Protocol, which calls for a phase-out of chlorofluorocarbons (CFCs) and other ozone-depleting chemicals by the year 2006. CFCs—first fingered as dangerous in the 1970s by Sherwood Rowland and Mario Molina, two of this year"s Nobel—prizewinning chemists—have been widely used for refrigeration and other purposes. If uncontrolled, the CFC assault on the ozone layer could increase the amount of hazardous solar ultraviolet light that reaches the earth"s surface, which would, among other things, damage crops and cause cancer in humans. Thanks to a sense of urgency triggered by the 1085 detection of what has turned out to be an annual "hole" in the especially vulnerable ozone over Antarctica, the Montreal accords have spurred industry to replace CFCs with safer substances. Yet the CFCs already in the air are still doing their dirty work. The Antarctic ozone hole is more severe this year than ever before, and ozone levels over temperate regions are dipping as well. If the CFC phase-out proceeds on schedule, the atmosphere should start repairing itself by the year 2000, say scientists. Nonetheless, observes British Antarctic Survey meteorologist Jonathan Shanklin: "It will be the middle of the next century before things are back to where they were in the 1970s". Developing countries were given more time to comply with the Montreal Protocol and were promised that they would receive $250 million from richer nations to pay for the CFC phase-out. At the moment, though, only 60% of those funds has been forthcoming. Says Nelson Sabogal of the U.N. Environment Program: "If developed countries don"t come up with the money, the ozone layer will not recuperate. This is a crucial time". It is also a critical time for warding off potentially catastrophic climate change. Waste gases such as carbon dioxide, methane and the same CFCs that wreck the ozone layer all tend to trap sunlight and warm the earth. The predicted results: an eventual melting of polar ice caps, rises in sea levels and shifts in climate patterns. In the eyes of the writer, the worsening atmosphere is something ______.
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The history of responses to the work of the artist Sandro Botticelli (1444～1510) suggests that widespread appreciation by critics is a relatively recent phenomenon. Writing in 1550, Vasari expressed an unease with Botticelli"s work, admitting that the artist fitted awkwardly into his evolutionary scheme of the history of art. Over the next two centuries, academic art historians defamed Botticelli in favor of his fellows Florentine, Michelangelo. Even when anti-academic art historians of the early nineteenth century rejected many of the standards of evaluation adopted by their predecessors, Botticelli"s work remained outside of accepted taste, pleasing neither amateur observers nor connoisseurs. (Many of his best paintings, however, remained hidden away in obscure churches and private homes.) The primary reason for Botticelli"s unpopularity is not difficult to understand: most observers, up until the mid-nineteenth century, did not consider him to be noteworthy, because his work, for the most part, did not seem to these observers to exhibit the traditional characteristics of fifteenth-century Florentine art. For example, Botticelli rarely employed the technique of strict perspective and, unlike Michelangelo, never used chiaroscuro. Another reason for Botticelli"s unpopularity may have been that his attitude toward the style of classical art was very different from that of his contemporaries. Although he was thoroughly exposed to classical art, he showed little interest in borrowing from the classical style. Indeed, it is paradoxical that a painter of large-scale classical subjects adopted a style that was only slightly similar to that of classical art. In any case, when viewers began to examine more closely the relationship of Botticelli"s work to the tradition of fifteenth-century Florentine art, his "reputation began to grow. Analyses and assessments of Botticelli made between 1850 and 1870 by the artists of the Pre Raphaelite movement, as well as by the writer Pater (although he, unfortunately, based his assessment on an incorrect analysis of Botticelli"s personality), inspired a new appreciation of Botticelli throughout the English-speaking world. Yet Botticelli"s work, especially the Sistine frescoes, did not generate worldwide attention until it was finally subjected to a comprehensive and scrupulous analysis by Home in 1908. Home rightly demonstrated that the frescoes shared important features with paintings by other fifteenth-century Florentines features such as skillful representation of anatomical proportions, and of the human figure in motion. However, Home argued that Botticelli did not treat these qualities as ends in themselves—rather, that he emphasized clear depletion of a story, a unique achievement and one that made the traditional Florentine qualities less central. Because of Home"s emphasis crucial to any study of art, the twentieth century has come to appreciate Bottieelli"s achievements. We can learn from the text that art critics have a history of ______.
[背景资料] 某河道工程项目法人按照《水利水电工程标准施工招标文件》(2009年版)编制了施工招标文件，招标文件规定不允许联合体投标。某投标人递交的投标文件由投标函及附录、授权委托书(含法定代表人证明文件)、投标保证金、项目管理机构、施工组织设计、资格审查资料、拟分包情况表、已标价工程量清单组成。投标文件拟将渠道混凝土砌块衬砌项目分包，填报了拟分包情况表。 经评标委员会评审，该投标人中标，并签订合同。施工期第一个月完成的项目和工程量(费用)如下： (1)80m3/h挖泥船施工，河道疏浚(4km，断面积48m2)； (2)施工期自然回淤清除(断面积2m2)； (3)河道疏浚超挖断面积(4m2)； (4)排泥管安装拆除，费用10万元； (5)开工展布，费用4万元； (6)施工辅助工程，包括浚前扫床和障碍物清除及其他辅助工程，费用50万元。 问题： 根据背景资料，施工期第1月不可以单独计算和支付的项目有哪些
[背景资料] 某综合利用水利枢纽工程位于我国西北某省，枯水期流量很少；坝型为土石坝，黏土心墙防渗；坝址处河道较窄，岸坡平缓。大坝采用碾压式填筑，坝体施工前，施工单位进行了碾压试验。施工中，坝体靠近混凝土涵管部位的土方填筑，需要采取技术措施以确保工程质量，工程中的某分部工程包括坝基开挖、坝基防渗及坝体填筑，该分部工程验收结论为“本分部工程划分为80个单元工程，其中合格30个，优良50个，主要单元工程、重要隐蔽工程及关键部位的单元工程质量优良，且未发生过质量事故；中间产品质量全部合格，其中混凝土拌合物质量达到优良，故本分部工程优良。” 问题： 根据水利水电工程有关质量评定规程，上述验收结论应如何修改
[背景资料] 某综合利用水利枢纽工程位于我国西北某省，枯水期流量很少；坝型为土石坝，黏土心墙防渗；坝址处河道较窄，岸坡平缓。大坝采用碾压式填筑，坝体施工前，施工单位进行了碾压试验。施工中，坝体靠近混凝土涵管部位的土方填筑，需要采取技术措施以确保工程质量，工程中的某分部工程包括坝基开挖、坝基防渗及坝体填筑，该分部工程验收结论为“本分部工程划分为80个单元工程，其中合格30个，优良50个，主要单元工程、重要隐蔽工程及关键部位的单元工程质量优良，且未发生过质量事故；中间产品质量全部合格，其中混凝土拌合物质量达到优良，故本分部工程优良。” 问题： 大坝施工前碾压实验主要确定哪些压实参数施工中坝体与混凝土泄洪闸连接部位的填筑，应采取哪些措施保证填筑质量
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