个人中心
个人中心
2020年1月4日
上午场托福考试
综合写作
重复2013-01-26真题
独立写作
重复2014-03-16真题
2020.01.04 综合写作
- 阅读主要观点提取-
总论点：American Burying Beetle快灭绝的原因的三个猜测。
猜测一：农业中使用的杀虫剂会毒死burying beetle。
猜测二：人类行为使得土地碎片化，破坏了burying beetle的栖息。
猜测三：scavenger mammals和burying beetle竞争食物，使得beetle食物越来越少。
- 听力主要观点提取 -
总论点：burying beetle数量减少的原因很神秘，但是阅读中提出的三个猜测都不对。
分论点一：虽然杀虫剂对环境有很大的影响，但是美国东北部beetle数量减少的时间点早于该地区开始使用杀虫剂的时间。
分论点二：在美国好几种甲壳虫和burying beetle相似，有着相似的生活模式。如果由于栖息地的碎片化就使得burying beetle数量减少，那么其他的甲壳虫也应该减少。但是其他类似的甲壳虫数量并未明显减少。
分论点三：burying beetle有一种特殊的特征，它们的嗅觉很厉害，它们能够在很远的地方就嗅到新鲜的食物。一旦发现食物，burying beetle会在食物上喷一种化学物质来掩盖住猎物的味道，这样scavenger就不能发现猎物，无法与burying beetle竞争食物。
上午场考试题目
会不会
在下午场重现
大概率是不会的，但曾经重复过
所以
我们建议下午场考生
进场前适当
关注一下上午场解析
而且
下面我们给出的是
华华独家整理的
[综合写作听力原文]
务必记住
[只有华华拥有2011-2019历年托福真题]
The decline of the American Burying Beetle is very mysterious. Unfortunately, none of the theories you read about can explain why the species is dying out.
First, the pesticide theory is appealing because pesticides definitely can have a powerful effect on the environment. But in the northeastern US, the decline of the beetle population began several years before the first chemical pesticides were introduced there. And in some areas of the Midwestern United States, the beetle population survived for 20 or 30 years after chemical pesticides became widely used there. So in at least two regions of the United States which one had very large beetle populations that pesticides don't seem to have a direct link with the beetles' decline.
Second, there's a problem with the development theory as well. In the United States, there are a number of beetle species related to the American Burying Beetle that have a very similar mode of life and live in very similar habitats. The habitats of these related beetle species have also been fragmented by development. However their populations have not declined significantly. If habitat fragmentation hasn't caused a decline in their related beetle species, there is no reason why it should have caused the decline of the American Burying Beetle.
Third, in thinking about that competition theory, it's important to consider some special characteristics of the burying beetle that the reading did not mention. The burying beetles have a powerful sense of smell, and they can locate new food sources very quickly and from long distances. Once the Beetles find the food, they spray it with a special chemical that blocks its smell. These smell-blocking chemical keeps animals such as the scavenger mammals from being able to find the food. With these important advantages over other species, it doesn't seem likely that increased numbers of competitors could affect the beetle so drastically.
