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10/12 bj 回报些许jj(有更新)

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11#
发表于 2009-10-13 12:15:00 | 只看该作者

感谢lz!

12#
发表于 2009-10-13 13:13:00 | 只看该作者
和楼主经历分数很像,一战710,二战750,只是我两次数学都是50.残念。。
13#
 楼主| 发表于 2009-10-13 13:32:00 | 只看该作者
哦 好像那个选项不是4是3 对 应该是3 因为我记得我拿5*6*7验证过了
以下是引用asiamba在2009/10/13 10:04:00的发言:

三个连续数相乘并不能保证有两个偶数的,所以应该只有选项2对

14#
 楼主| 发表于 2009-10-13 13:34:00 | 只看该作者
因为一共25个数的话,中位数应该是第十三个数吧
以下是引用doctortt在2009/10/13 10:04:00的发言:
Hi, why #41 is 8?

15#
 楼主| 发表于 2009-10-13 13:49:00 | 只看该作者
我印象里不太一样,可能就中间的1304的时间差不太多,在原文中就是第一段比较靠前的位置,引出科学家的发现。
以下是引用ohohh在2009/10/13 10:54:00的发言:

能不能帮忙确认下这段鸡骨头的结论和原文是否一致,有没有原文重现

Which came first–the chicken or the European?

Popular history, and a familiar rhyme about Christopher Columbus, holds that Europeans made contact with the Americas in 1492, with some arguing that the explorer and his crew were the first outsiders to reach the New World.

But chicken bones recently unearthed on the coast of Chile—dating prior to Columbus’ “discovery” of America and resembling the DNA of a fowl species native to Polynesia—may challenge that notion, researchers say.

Chickens could not have gotten to South America on their own—they had to be taken by humans,” said anthropologist Lisa Matisoo-Smith from the University of Auckland, New Zealand.

Polynesians made contact with the west coast of South America as much as a century before any Spanish conquistadors, her findings imply.

DNA in bone

The chicken bones were discovered at an archaeological site called El Arenal, on the south coast of Chile, alongside other materials belonging to the indigenous population. While chickens aren’t native to the region, it was believed the local Araucana species found there now was brought to the Americas by Spanish settlers around 1500.

Tests on the bones, however, now indicate the birds arrived well before any European made landfall in South America, Matisoo-Smith and her colleague Alice Storey found.

We had the chicken bone directly dated by radio carbon. The calibrated date was clearly prior to 1492,” Matisoo-Smith told LiveScience, noting that it could have ranged anywhere from 1304 to 1424. “This also fits with the other dates obtained from the site (on other materials), and it fits with the cultural period of the site.”

Did Polynesians continue eastwards?

DNA extracted from the bones also matched closely with a Polynesian breed of chicken, rather than any chickens found in Europe.

Polynesia was settled by sailors who migrated from mainland Southeast Asia, beginning about 3,000 years ago. They continued gradually eastwards, but were never thought to have journeyed further than Easter Island, about 2,000 miles off the coast of continental Chile.

The chicken DNA suggests at least one group did make the harrowing journey across the remaining stretch of Pacific, Matisoo-Smith said.

We cannot say exactly which island the voyage came from. The DNA sequence is found in chickens from Tonga, Samoa, Niue, Easter Island and Hawaii,” Matisoo-Smith said. “If we had to guess, we would say it was unlikely to have come from West Polynesia and most likely to have come from Easter Island or some other East Polynesian source that we have not yet sampled.”

The results are detailed in the latest issue of the journal Proceedings of the National Academy of Sciences.

Kon-Tiki trip in reverse

It might be the most tangible, but this isn’t the first evidence that pre-Columbian voyages from the Pacific to South America were possible.

In 1947, Thor Heyerdahl, the famous Norwegian anthropologist, made the voyage from Peru to Polynesia aboard his Kon-Tiki raft to prove the trip was doable with a rudimentary vessel.

There are more scientific arguments, too, said Matisoo-Smith.

There is increasing evidence of multiple contacts with the Americas,” she said, “based on linguistic evidence and similarities in fish hook styles.” Physical evidence of human DNA from Polynesia has yet to be found in South America, she added.

16#
 楼主| 发表于 2009-10-13 13:53:00 | 只看该作者
我能肯定的是作者不赞成第一段中提出的结论,而第二段则是用来批驳第一段的,最后好像有一个让步的句子,就是说即使第一段的什么什么假设正确,好像也不能说明波西米亚人先到美洲(印象里是这样)。
其中好像没有考到作者的观点吧,但是有一道题是问你哪个说法能够加强第一个结论,是个逻辑题。
以下是引用ohohh在2009/10/13 10:43:00的发言:
想问下楼主,鸡骨头那篇最后作者是赞成欧洲人先到美洲的,还是波西米亚人先到美洲,还是不确定波西米亚人怎么到的美洲

17#
 楼主| 发表于 2009-10-13 13:54:00 | 只看该作者
呵呵 我和你做的好像不太一样 我是把19.9替代成20,98.7替代成100,0.038近似成0.04,81.3近似成80
以下是引用coolboxer在2009/10/13 10:50:00的发言:

版本2
   

[(81.3*19.9*0.038)/98.7]^1/2 

0.08

0.064

0.64

0.8

我选的0.8

19.9替代成20,98.7替代成100,0.038还0.036,81.3还81


18#
发表于 2009-10-13 14:15:00 | 只看该作者

75.     图画不出来就是一个球横着切成三部分上下两部分完全一样问球半径还是直径来着

  条件一,切面直径(貌似)

  条件二,中间部分厚度给出,上面部分的高度

  作者选B因为厚度除以二加高度应该是半径了(待议)

条件1好像都可以啊   

拿出圆的纵截面,切面直径t的一半对着的圆心角应该是60度吧,t/sin60度  不就能求出球半径? 

应该选D?


[此贴子已经被作者于2009/10/13 14:15:51编辑过]
19#
发表于 2009-10-13 16:02:00 | 只看该作者
恭喜楼主啦。谢谢~
20#
发表于 2009-10-13 20:54:00 | 只看该作者

恭喜楼主吖

希望我后天也能拿个楼主这么高的分数

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