今天小编和大家详细介绍下
1. 高频长阅读Red Maple再现：
[1]. 提出旧理论，提出解释1反驳旧理论：美国东部的red maple越来越多，一种观点认为这个和全球二氧化碳的增多全球变暖有关，然后红枫树对这个很敏感，北美的红枫的光合作用加强，数量增多了(Some scientists think the increased atmospheric carbon dioxide help with photosynthesis of Maple Tree.)。However, this didn't cause the number of other trees in the same area to increase。说oak也对这个敏感，但却没有这种情况(But, the photosynthesis ability of Maple tree may not necessarily be better than oak trees.)，所以这种解释不成立。
[2]. 提出解释2反驳旧理论：another explanations contains很多方面，比如下面：
(1) The increase of red maple trees might be due to the suppressed fire rate in the recent years，因为红枫比起其他树木，对fire更敏感，要使红枫在火烧后能迅速恢复，火的控制对red maple的数量多当然有很大贡献。
(2) its unique capability to grow in both young and old forests, etc.
(3) The deer eat the foliage of oak trees in the summer and eat something from the maple tree in the winter (this is bad). However it is less harmful in the winter than in the summer for the trees.(deer要吃oak的seeds，特别在夏天，这时是oak发展最快的顶点，但是不吃红枫的seeds，只在冬天吃红枫的twig。red maple叶子分泌一个物质，deer?喜欢吃，所以red maple数量大，还有red maple产种子多)
1) 题目：文中提到"没有使同一地区的其他树木增加"这句话的作用是什么?
答案：为了说明第一种见解?正确。
2) 题目：与红枫树共同生长的树木不能怎么样?
答案：They cannot lavish in both young and mature forests.(原文：red maples have the unique 怎么怎么lavish in both young and mature forest.)
3) 题目：哪个是红枫树的特点?
答案：只有它能在young和 mature age都生长。
4) 题目：关于它的表述哪个是错误的
干扰选项：oak长的比红枫树快。
5) 题目：What is the purpose of mentioning other reasons other than carbon dioxide increase?
答案：To downplay the importance of carbon dioxide in the increase in red maple trees.
点评：此题为阅读超高频题，在去年的7,9,10,11四月都有考到，今年3月9日考到，4月27日考到，5月4日考到，这次又出现了!所以大家一定要仔细研读咯。
2. 高频机经snowshoe hare population，下面是文章原文：
The snowshoe hare is one of the northern mammals that go through periodic cycles of changes in their populations. Over a period of years, their population will increase in numbers and then suddenly crash to very low numbers, only to rise again. Snowshoe hare tend to cycle about once every ten years. The snowshoe hare cycle is one of the best known and fur trappers and traders working in northern Canada first described it. In 1865, traders with the Hudson's Bay Company were flooded by hare pelts brought in by trappers. But, by 1870, only a few hare pelts trickled in. This pattern of high and low abundance of hare pelts repeated itself over and over, roughly every ten years.
Snowshoe hares are a dominant herbivore in northern forest ecosystems. In Alaska and western Canada, their populations cycle over 8 to 11 years. The difference in densities and abundance during the cycle are extreme. Densities as high as 4,000 hares per square kilometer (or 10,000 hares per square mile) have been estimated at the peak (or high point) of the cycle. These populations can "crash" to densities of less than one hare per square kilometer (or 2.6 hares per square mile) within a period of one year. The populations slowly increase to peak densities over the next 6 to 13 years. The densities during peak years, however, are not always the same.
Just what is it that drives the snowshoe hare cycle? This question has puzzled people living in northern areas and scientists for many years. On a broad scale, it may be the 22- year sunspot cycle and its effects on boreal forest weather patterns or forest fires. On a smaller scale, the cycles may be affected by over browsing the food supply, predators, shock disease due to stress, parasites, or a combination of these. The primary theory pertaining to the snowshoe hare population cycle describes the mechanics as a combination of predators and browse (food) availability. During the peak of their cycle, hares eat a large proportion of the shrubs available in their area. They can also kill many of the shrubs in their area by chewing through the outer layer of bark. Over-browsing of shrubs results in a food-shortage that causes malnourishment, starvation, and reduced reproduction. This leads to the start of the population crash or decline. Also, as food supplies decrease, the health of hares declines and makes many individuals more vulnerable to predators and disease. In the western Yukon, scientists believe that the hare cycle is caused by changes in food supply and predation. The declines and increases in the population of hares were influenced by the reproductive rates of adult hares and the survival rates of all ages of hares.
点评：大家可以把这篇文章好好研究下，虽然问题从缺，但是题目读透了做题也就不难了。
3. Maya文明
[1]. 提出旧理论：老观点认为 Maya人很和平，Maya文化灭绝是大灾难的影响。
[2]. 提出新理论：玛雅是因为战争等等人为因素导致灭亡，证据就是在那个石头记载之后还有人的痕迹。后来发现是一系列原因造成灭亡的，而且在停止修建大型建筑后还有各种发展和生活活动。
题目：作者没有争论第一点。(哪个能够 support 作者观点)
答案：最后一个石头记载的那个时间，这个是历史事实，不能否认。
点评：玛雅文明的题材在考试中考的非常多，。
以上就是小编今天的分析。
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