新东方在线网络课堂 托福 新东方在线 > 托福 > 托福精选 > 正文

科学美国人60秒:爬山熊帮助樱桃树种子迁徙-托福听力下载

2016-11-25 13:03:59 来源:科学美国人60秒托福资料下载

点击查看>>科学美国人60秒音频:爬山熊帮助樱桃树种子迁徙

  科学美国人60秒中英文翻译:爬山熊帮助樱桃树种子迁徙

  科学美国人60秒英文文本

  Picture a brave fireman carrying a pet from a burning building.

  Now, imagine that global warming is the burning building, a cherry tree is the pet, and a bear is the fireman.

  You've now got the gist of a new study that finds that cherry trees may be able to survive rising temperatures thanks to mountain-climbing bears that carry the cherry tree seeds to cooler climes.

  It's projected that, over the next hundred years, temperatures on Earth could rise an average of nearly five degrees Celsius.

  While some animals might be able to migrate north to escape the brunt of the heat, plants can't uproot themselves quite so easily.

  But researchers wondered whether the creatures that disperse plant seeds might be able to help.

  So scientists spent three years sifting through the droppings of Asiatic bears, looking for cherry tree seeds.

  And they found that the bears were indeed transporting the seeds to cooler locations—not by moving to higher latitudes, but higher altitudes.

  Seems the bears snack on the fruits that are found at the foot of the mountains in spring and then make the climb to higher elevations to enjoy young leaves and buds and flowers, particularly as the season progresses.

  The researchers could tell that seeds had been deposited higher up the mountain than they had been harvested by the ratio of their oxygen isotopes, which changes with altitude.

  And the 300 or so meters the seeds ascended should buy the resulting trees a degree or two in heat relief.

  The study is in the journal Current Biology.

  The finding is good news for plants, like cherry trees, that fruit in spring.

  Unfortunately, the results suggest that plants that fruit in fall, when bears are headed back down for hibernation, will have to hold out for a different animal hero.

  Or for a bear with a bad sense of direction.

  中文翻译请点击下一页

本文关键字: 科学美国人60秒 科学60秒下载 托福听力

为你特别匹配的托福超值课程,快速提分先人一步!
  • 大学生旗舰直达冲100分

    【知心托福】大学生旗舰直达冲100分

    适合人群:托福目标分数100!!!

    课程特色:推送补充相应知识点,有效提升学习效率。

    查看详情
  • 【知心托福】大学生旗舰直达冲90分

    【知心托福】大学生旗舰直达冲90分

    适合人群:托福目标分数90!!!

    课程特色:推送补充相应知识点,有效提升学习效率。

    查看详情
  • 【21天冲分】 21天直冲托福100+

    【21天冲分】 托福2018年6月临考急训25人班

    适合人群:参加过托福考试或基础段的学习,距离最新考试仅剩1个月时间,急需短期内快速高效冲分的考生。

    特点:全科直播24小时

    查看详情
  • TOEFL6月早练团

    【早练团】TOEFL6月早练团

    课程特色:高能学习的正确打开方式,早练早提分!

    课时:28课时(每天0.5小时,5月共上课28天)

    查看详情
  • 大学生旗舰直达班 (冲110分)

    【知心托福】大学生旗舰直达班 (冲110分)

    适合人群:托福目标分数110分!

    课时:343

    查看详情

课程试听换一换

  • 知心托福 大学生旗舰直达班 (冲110分)

    ¥8280

  • 知心托福 直达班(冲110分)

    ¥4380

  • 知心托福 精品直达班(冲110分)

    ¥5880

  • 知心托福 大学生旗舰直达班 (冲100分)

    ¥7980

  • TOEFL 6月早练团-单日“听力团”+双日...

    ¥28

  • 知心托福 直达班(冲100分)

    ¥4080

  • 知心托福 中学生旗舰直达班 (冲110分)

    ¥8280

  • 知心托福 直达班(冲90分)

    ¥3880

分享到:

相关推荐

交流 • 下载

精品课限量免费领

  • 托福听力备考全攻略
  • 托福考试指南_托福新生必修课
  • 新东方雅思托福GRE词汇量在线测试

提分历程更多>>

实用 • 工具

托福课程排行榜本周本月

托福公开课更多>>

新东方在线知心托福介绍说明【热】 w 04分14秒
1 新东方在线知心托福介绍说明【热】
新东方在线唐悦宁:托福词汇遗忘规律 w 07分34秒
2 新东方在线唐悦宁:托福词汇遗忘规律
新东方在线唐悦宁:词根词缀记忆法 w 04分42秒
3 新东方在线唐悦宁:词根词缀记忆法
新东方在线唐悦宁:托福听力基础预备 w 03分30秒
4 新东方在线唐悦宁:托福听力基础预备
新东方在线李镇江:托福听力场景概述-社会科学-美国历史 w 08分35秒
5 新东方在线李镇江:托福听力场景概述-社会科学-美国历史

推荐阅读