关闭图标
log图标

toefl.viplgw.cn

  • 使用手机注册
  • 使用邮箱注册
  • 手机号不能为空!

    验证码不能为空!

    用户名不能为空!

    密码不能为空!

  • 邮箱不能为空!

    验证码不能为空!

    用户名不能为空!

    密码不能为空!

已有账号? 登录到雷哥托福
关闭图标
log图标
  • 使用手机找回密码
  • 使用邮箱找回密码
  • 手机号不能为空!

    验证码不能为空!

    密码不能为空!

  • 邮箱不能为空!

    验证码不能为空!

    密码不能为空!

又想起来了
加入生词本

listen

英['lɪs(ə)n] 美['lɪsn]
vi. 听,倾听;听从,听信
n. 听,倾听

已添加
×

我要举报草莓小菇凉评论

用户头像
草莓小菇凉:说的非常好,十分有道理,棒棒棒!

06-08 15:44:55

请选择举报类型:

举报电话:400-6021-727    举报QQ:2095453331
×
logo图标
分享到雷哥托福

分享成功图标分享成功

邀请名师点评成功,管理员正在安排老师进行点评。

继续做题 返回首页
支付雷豆失败图标 雷豆余额不足 购买雷豆 返回
报告题目错误
请选择错误类型:
请描述一下这个错误:

取消

TPO-11- Orientation and Navigation

To South Americans, robins are birds that fly north every spring. To North Americans, the robins simply vacation in the south each winter. Furthermore, they fly to very specific places in South America and will often come back to the same trees in North American yards the following spring. The question is not why they would leave the cold of winter so much as how they find their way around. The question perplexed people for years, until, in the 1950s, a German scientist named Gustave Kramer provided some answers and, in the process, raised new questions.

Kramer initiated important new kinds of research regarding how animals orient and navigate. Orientation is simply facing in the right direction; navigation involves finding ones way from point A to point B.

Early in his research, Kramer found that caged migratory birds became very restless at about the time they would normally have begun migration in the wild. Furthermore, he noticed that as they fluttered around in the cage, they often launched themselves in the direction of their normal migratory route. He then set up experiments with caged starlings and found that their orientation was, in fact, in the proper migratory direction except when the sky was overcast, at which times there was no clear direction to their restless movements. Kramer surmised, therefore, that they were orienting according to the position of the Sun. To test this idea, he blocked their view of the Sun and used mirrors to change its apparent position. He found that under these circumstances, the birds oriented with respect to the new "Sun." They seemed to be using the Sun as a compass to determine direction. At the time, this idea seemed preposterous. How could a bird navigate by the Sun when some of us lose our way with road maps? Obviously, more testing was in order.

So, in another set of experiments, Kramer put identical food boxes around the cage, with food in only one of the boxes. The boxes were stationary, and the one containing food was always at the same point of the compass. However, its position with respect to the surroundings could be changed by revolving either the inner cage containing the birds or the outer walls, which served as the background. As long as the birds could see the Sun, no matter how their surroundings were altered, they went directly to the correct food box. Whether the box appeared in front of the right wall or the left wall, they showed no signs of confusion. On overcast days, however, the birds were disoriented and had trouble locating their food box.

In experimenting with artificial suns, Kramer made another interesting discovery. If the artificial Sun remained stationary, the birds would shift their direction with respect to it at a rate of about 15 degrees per hour, the Sun's rate of movement across the sky. Apparently, the birds were assuming that the "Sun" they saw was moving at that rate. When the real Sun was visible, however, the birds maintained a constant direction as it moved across the sky. In other words, they were able to compensate for the Sun's movement. This meant that some sort of biological clock was operating-and a very precise clock at that.

What about birds that migrate at night? Perhaps they navigate by the night sky. To test the idea, caged night-migrating birds were placed on the floor of a planetarium during their migratory period. A planetarium is essentially a theater with a domelike ceiling onto which a night sky can be projected for any night of the year. When the planetarium sky matched the sky outside, the birds fluttered in the direction of their normal migration. But when the   dome was rotated, the birds changed their direction to match the artificial sky. The results clearly indicated that the birds were orienting according to the stars.

There is accumulating evidence indicating that birds navigate by using a wide variety of environmental cues. Other areas under investigation include magnetism, landmarks, coastlines, sonar, and even smells. The studies are complicated by the fact that the data are sometimes contradictory and the mechanisms apparently change from time to time. Furthermore, one sensory ability may back up another.

对南美人来说,知更鸟是每年春天向北飞的鸟。对于北美人来说,罗宾斯每个冬天都只是在南方度假。此外,他们飞往南美洲的特定地点,往往会在次年春天回到北美洲的同一棵树上。问题不在于他们如何摆脱冬天的寒冷,而在于如何找到自己的方向。这个问题多年来困扰人们,直到20世纪50年代,德国科学家古斯塔夫·克雷默(Gustave Kramer)提供了一些答案,并在此过程中提出了新的问题。

 

克雷默发起了关于动物如何定位和导航的重要的新型研究。方向只是面向正确的方向;导航包括找到从A点到B点的路线

 

在他的研究初期,克莱默发现笼养的候鸟在大约通常在野外开始迁徙的时候变得非常不安。此外,他注意到,当他们在笼子里晃动时,他们往往向正常的迁徙路线的方向发起自己。然后他与囚禁的椋鸟进行实验,发现其方向实际上是在适当的迁徙方向上,除了天空阴沉的时候,他们不安的动作没有明确的方向。因此,克莱默推测,他们正在根据太阳的位置来定位。为了验证这个想法,他阻止了他们对太阳的看法,并用镜子改变了它的明显位置。他发现,在这种情况下,这些鸟儿相对于新的“太阳”他们似乎在用太阳作为指南来确定方向。当时,这个想法似乎荒谬。当一些人在路线图上迷失方向时,一只鸟如何能够在太阳下航行?显然,更多的测试是为了。

 

因此,在另一组实验中,克莱默将相同的食品盒放在笼子周围,只在一个盒子里放入食物。盒子是静止的,而那个装着食物的盒子总是在指南针的同一点。然而,它可以通过旋转装有鸟类的内笼或作为背景的外壁来改变其相对于周围环境的位置。只要鸟儿能看到太阳,不管周围的环境如何变化,他们就直接走向正确的食物盒。不管箱子是出现在右墙还是左墙的前方,都没有出现混淆的迹象。然而,在阴天,鸟儿迷失方向,无法定位食物盒。

 

在试验人造太阳时,克莱默又发现了一个有趣的发现。如果人造太阳保持静止状态,那么鸟类会以每小时15度的速度,即太阳在天空中的移动速度来改变方向。显然,这些鸟儿正在假设他们看到的“太阳”正在以这样的速度前进。然而,当真正的太阳可见时,鸟儿在天空中移动时保持不变的方向。换句话说,他们能够弥补太阳的运动。这意味着某种生物钟正在运行 - 并且是一个非常精确的时钟。

 

那么夜间迁徙的鸟类呢?也许他们在夜空中航行。为了验证这个想法,笼养的夜间迁徙鸟类在迁徙期间被放置在天文馆的地板上。天文馆本质上是一个有圆顶状天花板的剧院,一年中任何一个夜晚都可以投射夜空。当天文馆的天空与外面的天空相匹配时,鸟儿就朝正常的迁徙方向飘扬。但是当圆顶旋转时,鸟儿改变方向匹配人造天空。结果清楚地表明,鸟类正在按照星星的方向。

 

有越来越多的证据表明,鸟类通过使用各种各样的环境线索进行导航。其他正在调查的领域包括磁性,地标,海岸线,声纳,甚至是气味。由于这些数据有时是矛盾的,而且这些机制显然会不时变化,因此研究变得复杂起来。此外,一种感官能力可能会支持另一种感觉能力。


中文翻译

Which of the following can be inferred about bird migration from paragraph 1?

  • To South Americans, robins are birds that fly north every spring. A Birds will take the most direct migratory route to their new habitat. B The purpose of migration is to join with larger groups of birds. C Bird migration generally involves moving back and forth between north and south. D The destination of birds' migration can change from year to year.
正确答案: C

网友解析

  • 用户头像

    big1008  发表于 2018-08-27 15:54:20

    1.这道题的关键词明显不是很好找,而且排除法的话答案又太长,所以看本段的开头,说南美的鸟春天飞去北方,而北美的鸟冬天飞去南方,所以答案是C,between north and south,其他的选项都没有相关信息

  • 用户头像

    joannazz  发表于 2018-01-03 14:36:18

    推断题
    解析:文章开头到The question前都在讲robins这类鸟的迁徙,根据选项定位判断。AB没说。C文章中说robins春天在北方,冬天在南方,所以C对。D原文说back to the same trees,所以destination没有改变,D错

题目讨论

雷哥托福微信

  • 微信公众号:toeflgo

    二维码
  • 小托君:Toefl12345

    二维码
查看详情图片

您已提交评论成功

确定