小编为考生们整理一文是关于新
新
主题:Carolina bays是否由于meteorite explosion造成
R&L对照
Reading: 是
1、Asymmetrical depressions。
2、Carolina bays的沙子和其他地方的不一样,没有iron coat是因为爆炸使它melt了。
3、Carolina bays有很多buckyball,是carbon的特殊形式,由于爆炸产生的。
Lecture: 反驳。
1、有可能是别的原因造成asymmetrical depressions,比如水flow,而且也有证据说明当时有underwater存在。
2、如果是melt的话会有glass存在,但是并没有发现,而沙子没有iron coat可能是因为chemical reaction。
3、buckyballs只有一些bay里才有。
新托福写作题目回忆版本二:
【阅读主要观点提取】
总论点:“Carolina bays”是指成千上万在美国东部的圆形或者椭圆形的洼地。科学家们一直很想知道这些洼地是如何形成的。有些人认为陨石撞击地球可以解释这些洼地的形成。阅读中给出了三个理由。
理由一:这些洼地是不对称的。一边的白沙总是高于另一边。众所周知,陨石撞击是可以形成一个不对称的坑的。
理由二:陨石撞击可以解释为什么在洼地边的沙子和美国东部的大部分沙子不一样。大部分的沙的表面有一层薄薄的铁,但是在洼地边的白沙就没有。支持陨石撞击理论的人猜测是因为陨石撞击时产生的强烈高温燃烧了白沙表面的铁。
理由三:人们在一些洼地里发现了巴基球。巴基球是一种碳的特殊形式。当碳受到巨大压力是,碳的形式就会变成巴基球。陨石撞击时产生的里足以让碳变成巴基球。
【听力主要观点提取】
总论点:并不是陨石撞击产生了“Carolina bays”
解释一:如果水一直向一个方向流,洼地也会出现一边高一边低的现象。存在洼地的区域曾经都是充满着地下水,很有可能是深海的水流牵引着洼地的水流,从而导致洼地的水流一直想一个方向移动。
解释二:如果温度可以非常高,那么铁就会被融化成玻璃。也就是说,是其他原因使得沙子表面的铁消失而不是高温。
解释三:仅仅在少数的洼地发现了巴基球。如果真的是陨石撞击形成了洼地,那么每一个洼地里都应该有巴基球,然而事实并非如此。同时还有一些其他原因可以形成巴基球,比如闪电。所以,少数洼地有巴基球可能是因为闪电。
新托福综合写作范文
The reading shows three features of “Carolina bays” to explain why meteorite impact cause these depressions. On contrary, the professor thinks all of them are unconvincing.
First, the writer states that the depressions are asymmetrical: the sand being higher on one side of the depression than the other, which caused by meteorite impact. However, the professor points out that another phenomenon also can explain this asymmetrical pattern. In fact, the areas containing the depressions were once underwater. So, deep sea current gradually dug the depressions and deposited sand in the direction of the current.
Second, the author demonstrates that intense heat created by meteorite impacts burned the iron out of the sand. But the speaker contradicts this point by saying that the amount of heat needed to burn the iron coating off sand grains is so high that it would melt the sand into glass. However, the problem is the evidence of glass doesn't be found in the depressions. Therefore, it’s possible that iron is removed by some chemical process.
Third, the professor refuses the viewpoint showed in the passage by claiming that the buckyball evidence is found in a few the “Carolina Bays”. If buckyballs are formed because of meteorite impact, each of the depression should have them. Furthermore, the buckyballs in a few depressions may be caused by lightning. (221 words)
另外有一则好消息,针对托福备考,