微信:liulangji8899
  • 托福频道
    • 托福阅读
    • 托福听力
    • 托福写作
    • 托福口语
    • 托福真题
    • TPO
  • 雅思频道
    • 雅思阅读
    • 雅思写作
    • 剑桥雅思
    • 雅思听力
    • 雅思真题
    • 雅思口语
    • 雅思电子书
  • SAT频道
    • 2016SAT真题
    • 2017SAT真题
    • 2018SAT真题
    • 2019SAT真题
    • 2020SAT真题
    • 2021SAT真题
    • 2022SAT真题
  • AP频道
    • AP化学真题
    • AP统计学真题
    • AP生物真题
    • AP英语语言真题
    • AP心理学真题
    • AP物理真题
    • AP经济学真题
  • ACT真题
导航
TOEFL IELTS SAT真题 AP真题 ACT真题
托福资讯
  • 托福阅读
  • 托福听力
  • 托福写作
  • 托福口语
  • 托福真题
  • TPO
托福阅读 托福听力 托福写作 托福口语 托福真题 TPO +
当前位置: 首页 > 托福频道 > 托福阅读

托福阅读真题+题目+答案:Dead Zones in the Sea

2020-11-01 来源:toefl.socool100.com

托福阅读真题+题目+答案:Dead Zones in the Sea

托福阅读真题+题目+答案:Dead Zones in the Sea

Many cities depend on nearby rivers to carry away waste. It eventually reaches the sea, where it provides nutrients for plankton (small organisms that drift in water), causing plankton blooms (rapid and excessive increases in plankton populations). When plankton die and sink into deeper water, they decompose in a process that uses oxygen. As a result, the water beneath plankton blooms often becomes anoxic (lacking oxygen) and thus devoid of life. These dead zones" now occur permanently or seasonally at over four hundred places worldwide, and one of the largest forms annually where the Mississippi River meets the sea. Dead zones form most readily where water is stagnant (moves little) and separated into nonmixing layers. Stagnant pools near the seabed eventually lose their oxygen as the sinking plankton build into piles. Despite their massive nutrient flows to the ocean, the Orinoco and Amazon Rivers have no dead zones, because water is pushed offshore too fast for oxygen to be lost. Where the flows of once great rivers have been greatly reduced by dams, cities, and crops along their course, areas where rivers flow into seas may hold water long enough for dead zones to form. This is the case, sadly, for rivers like the Loire in France and Po in Italy, when their lack of oxygen suppresses life in thousands of square kilometers of seabed every summer.

Paragraph 1 suggests which of the following about dead zones?

A.They could be reduced by providing more nutrients for plankton.

B.They often move great distances along with water flowing from one part of the ocean to another.

C.They are more numerous now than they were in the past.

D.They are more common on the surface of the ocean than they are beneath the surface.

 

According to paragraph 1, which of the following is true about the area where the Mississippi River meets the sea as compared to the areas where the Orinoco and Amazon Rivers meet the sea?

A.Water is more stagnant there.

B.This area receives fewer nutrients from the river.

C.There is a relatively high amount of oxygen in the water there.

D.Surface water mixes relatively easily with water near the seabed there.

 

Enclosed seas like the Baltic, Adriatic, and Black also suffer problems of stagnation.▋Shaped like a deep bowl that is cut off from the Mediterranean by a shallow underwater ridge in the Bosporus Strait, the Black Sea was a freshwater lake when sea levels went down fairly dramatically during the last glaciation (an extremely cold period during which much of Earth's water was locked in ice sheets). ▋It refilled eventually, with saltwater, in a catastrophic flood seven thousand years ago, when the Mediterranean rose high enough to break through the Bosporus. Massive floods triggered a tremendous human migration, and the event may be recorded in the ancient tale of Gilgamesh. ▋Today only a warm, less salty, surface layer is well oxygenated and able to support abundant life. ▋This low-density layer sits over the cooler, saltier waters of the deep basin like a lid and has suffocated life below. Deeper than about 150 meters, the Black Sea is devoid of oxygen.

。。。。。余下托福阅读真题原文及题目答案省略!

完整版托福阅读真题+题目+答案:Dead Zones in the Sea下载,10元有偿!

微信扫码支付

支付宝扫码支付

资料下载说明
  • 一般发网盘,邮箱,微信
  • 支付成功后,请加微信客服:liulangji8899
  • 微信客服一般都能及时回复
  • 文章关键词
  • 托福阅读真题+题目+答案:Dead Zones in the Sea
  • 你可能感兴趣的文章
    • 托福阅读真题+题目+答案:Evolution in Peppered Moths
    • 托福阅读真题+题目+答案:The Development of Land Flora
    • 托福阅读真题+题目+答案:Dams and Flood Control
    • 托福阅读真题+题目+答案:Bumblebee Heat Regulation
    • 2021年6月22日托福阅读真题+题目+答案:The Early Cyclades 
    微信客服
    头条推荐
    • 2020年7月11日雅思小作文范文:The table below shows oil production in several African countries (barrels per day
    • 2020年7月11日雅思阅读真题+题目+答案:Stress of Workplace
    • 剑桥雅思真题15+答案解析PDF下载(高清无水印完整版)
    • 2013年1月5日雅思小作文题目:The charts give information about the reasons why people leave the UK and why peopl
    • 2014年托福阅读真题+题目+答案解析:The Beringia Landscape
    • 2014年托福阅读真题+答案解析+翻译:Agricultural Society in Eighteenth-Century British America

    托福资料

    托福听力真题 托福阅读真题 托福写作范文 托福口语范文 托福TPO 托福电子书

    雅思资料

    雅思阅读 雅思写作 剑桥雅思 雅思听力 雅思口语 雅思电子书

    SAT资料

    2016SAT真题 2017SAT真题 2018SAT真题 2019SAT真题 2020SAT真题 2021SAT真题 2022SAT真题

    AP资料

    AP化学真题 AP统计学真题 AP生物真题 AP英语语言真题 AP心理学真题 AP物理真题 AP经济学真题
    添加客服微信
    Email : foeveryoung18@outlook.com (I will reply you within 1-8 hours)
    皖ICP备2022007860号
    ©2020 socool00.com
    皖ICP备2022007860号
      热门资料
    • 托福真题
    • 雅思真题
    • SAT真题
    • AP真题
    添加客服微信
    • Email : foeveryoung18@outlook.com (I will reply you within 1-8 hours)
    • 皖ICP备2022007860号