首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
The Exploding Lakes of Cameroon What comes to mind when you think of a lake?...
The Exploding Lakes of Cameroon What comes to mind when you think of a lake?...
admin
2020-12-24
37
问题
The Exploding Lakes of Cameroon
What comes to mind when you think of a lake? You probably imagine a pretty scene with blue water, birds, and fish. For the people in the northwestern Cameroon, however, the image is very different. For them, lakes may mean terrible disasters. In 1984, poisonous gases exploded out of Lake Monoun and came down into the nearby villages, killing thirty-seven people. Two years later, Lake Nyos erupted. A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.
Lake Nyos and Lake Monoun are crater (火山口)lakes. They were formed when water collected in the craters of old volcanoes. The volcanoes under Lake Nyos and Lake Monoun are not active anymore. However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake. This is normal in a crater lake. In most crater lakes, these gases are released often because the water “turns over” regularly. That is, the water from the bottom of the lake rises and mixes with the water at the top, allowing the gases to escape slowly.
However, in Lakes Nyos and Monoun,there is no regular turning over. No one knows the reason for this fact, but as a result, these lakes have more gases trapped at the bottom than other crater lakes. In fact, scientists who have studied Lakes Nyos and Monoun have found 16, 000 times more gases. When a strong wind, cool weather, a storm, or a landslide (滑坡)causes the water to turn over suddenly, the gases escape in a violent explosion.
In the past, no one knew when the gases might explode, so there was no way for the villagers to escape disaster. Now scientists from the United States, France, and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos. They stood a 672-foot plastic pipe in the middle of the lake, with one end of the pipe near the bottom and the other end in the air. Near the top of the pipe, the team put several holes that could be opened or closed by a computer. Now, when the gas pressure gets too high, the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain. With less pressure, a disastrous explosion is much less likely. However, the scientists are not sure that one pipe will be enough to prevent explosions. They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.
To protect people nearby until all of the pipes are in place, the scientists have installed early warning systems at both lakes. If the gas pressure rises to a dangerous level, computers will set off loud sirens (警报)and bright lights to warn the people in the villages. That way, they will have time to escape from the dangerous gases.
What do we learn from the last paragraph?
选项
A Scientists are planning to install pipes in all crater lakes.
B Scientists still do not know how to prevent gas explosions.
C Explosion disasters could be avoided in the future.
D Warning systems have been set up in the villages nearby.
答案
C
解析
本题问的是在文章最后一段我们了解到了什么?文章最后一段主要讲的是在所有的湖里竖起缓解湖底气压的管子后,就不会有危险。故答案为C。
转载请注明原文地址:https://ti.zuoweng.com/ti/cmlQKKKQ
相关试题推荐
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
TheExplodingLakesofCameroon Whatcomestomindwhenyouthinkofalake?...
共用题干 TheExplodingLakesofCameroonWhatcomestomindwhenyouthinkofal...
共用题干 TheExplodingLakesofCameroonWhatcomestomindwhenyouthinkofal...
随机试题
利福平抗结核作用的特点是 A.选择性高 B.穿透力强 C.抗药性缓慢 D
华兴股份有限公司因经营管理不善造成亏损,且未弥补的亏损达公司股本的1/4。公司董
某项目的招标人于2008年6月1日向中标人发出了中标通知书,双方于2008年6月
根据企业风险管理基本框架八个方面的内容基金管理人要求公司基金经理与特定资产管理业
下列关于法律的说法正确的有( )。
依据《刑法》的规定,未经注册商标所有人许可,在同一种商品上使用与其注册商标相同的商标,情节特别严重的,处()有期徒刑,并处罚金。A.3年以下B.7年以下
下列事项中,属于或有事项的有( )。A.对债务单位提起诉讼B.对售出商品提供售后担保C.无形资产摊销D.为子公司的贷款提供担保E.亏损合同F.固定资
在计征个人受赠不动产个人所得税时,可以核定征收。()
()利用惯性原理,对企业人力资源需求总量进行预测。A:趋势外推法B:人员比率法C:回归分析法D:经济计量模型法
计算净现金流量,应考虑下列哪些因素?()A.工作收入B.理财收入C.偿还利息D.购买股票E.变卖房产