大学英语六级分类模拟题420
Part Ⅰ Writing
1、Directions: For this part, you are allowed 30 minutes to write an essay commenting on the remark "There isn't anything noble about being superior to another person. True nobility is in being superior to the person you once were." You can give examples to illustrate your point and then explain what you will do to stay modest. You should write at least 150 words but no more than 200 words. Write your essay on Answer Sheet 1.
2、Directions银杏湖: For this part, you are allowed 30 minutes to write an essay on perverance by referring to the saying "What you do every day matters more than what you do every once in a while." You can cite examples to illustrate your point and then explain what you will do to enhance your perverance. You should write at least 150 words but no more than 200 words. Write your essay on Answer Sheet 1.
3、Directions: For this part, you are allowed 30 minutes to write an essay commenting on
the saying "Better three hours too soon than a minute too late." You can cite examples to illustrate your point. You should write at least 150 words but no more than 200 words.
4、Directions: For this part, you are allowed 30 minutes to write an essay entitled On Aiming Higher by commenting on the saying "Who aims at excellence will be above mediocrity; who aims at mediocrity will be far short of it." You should write at least 150 words but no more than 200 words.
5、 Directions: For this part, you are allowed 30 minutes to write a short essay on the major ranking in university. You should write at least 150 words but no more than 200 words. Write your essay on Answer Sheet 1.
Part Ⅱ Reading Comprehension
Blowing Hot and Cold
A. Climate change may be slow and uncertain, but that is no excu for inaction. One reason why uncertainty over climate change looks to be with us for a long time is that the 康定
唐雪利oceans, which absorb carbon from the atmosphere, act as a time-delay mechanism. Their massive thermal inertia means that the climate system responds only very slowly to changes in the composition of the atmosphere. Another complication aris from the relationship between carbon dioxide (CO护肤小技巧2), the principal greenhou gas (GHG., and sulphur dioxide (SO2我和她的传奇情仇电视剧), and a common pollutant. Efforts to reduce man-made emissions of GHGs by cutting down on fossil-fuel u will reduce emissions of both the gas. The reduction in CO2 will cut warming, but the concurrent SO2 cut may mask that effect by contributing to the warming.
B. There are so many such fuzzy factors—ranging from aerosol particles to clouds to cosmic radiation—that we are likely to e disruptions of familiar climate patterns for many years without knowing why they are happening or what to do about them. Tom Wigley, a leading climate scientist and member of the UN's Intergovernmental Panel on Climate Change (IPCC., goes further. He argues in an excellent book published by the Aspen Institute, "US Policies on Climate Change: What Next?", that whatever policy changes governments pursue, scientific uncertainties will "make it difficult to detect the eff小草的特点
ects of such changes, probably for many decades."
C. As evidence, he points to the negligible short-to medium-term difference in temperature resulting from an array of emission "pathways" on which the world could choo to embark if it decided to tackle climate change. He plots various strategies for reducing GHGs that will lead in the next century to the stabilization of atmospheric concentrations of CO2 at 550 parts per million (ppm). That is roughly double the level which prevailed in preindustrial times, and is often suggested by climate scientists as a reasonable target. But even by 2040, the temperature differences between the various options will still be tiny—and certainly within the magnitude of natural climatic variance. In short, in another four decades we will probably still not know if we have over-or under-shot.
D. However, that does not mean we know nothing. We do know, for a start, that the "greenhou effect" is real: without the heat-trapping effect of water vapor, CO2, methane and other naturally occurring GHGs, our planet would be a lifeless 30℃ or so colder. So柔拼音
我们心在一起me of the GHG emissions are captured and stored by "sinks", such as the oceans, forests and agricultural land, as part of nature's carbon cycle.
E. We also know that since the industrial revolution began, mankind's actions have contributed significantly to that greenhou effect. Atmospheric concentrations of GHGs have rin from around 280ppm two centuries ago to around 370ppm today, thanks chiefly to mankind's u of fossil fuels and, to a lesr degree, to deforestation and other land-u changes. Both surface temperatures and a levels have been rising for some time.
