首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Geologists have been studying volcanoes for a long time. Though they have learned a great deal, they still have not discovered t
Geologists have been studying volcanoes for a long time. Though they have learned a great deal, they still have not discovered t
admin
2015-12-31
76
问题
Geologists have been studying volcanoes for a long time. Though they have learned a great deal, they still have not discovered the causes of volcanic action. They know that the inside of the earth is very hot, but they are not sure exactly what causes the great heat. Some geologists have thought that the heat is caused by the great pressure of the earth’s outer layers. Or the heat may be left from the time when the earth was formed. During the last sixty years scientists have learned about radium (镭), uranium (铀), thorium (钍), and other radioactive elements. These give out heat all the time as they change into other elements. Many scientists now believe that much of the heat inside the earth is produced by radioactive elements.
Whatever the cause of the heat may be, we do know that the earth gets hotter the farther down we dig. In deep mines and oil wells the temperature rises about 1 F. for each 50 feet. At this rate the temperature 40 miles below the earth’s surface would be over 4 000 F.. This is much hotter necessary to melt rock. However, the pressure of the rock above keeps most materials from melting at their usual melting points. Geologists believe that the rock deep in the earth may be plastic, or puttylike. In other words, the rock yields slowly to pressure but is not liquid. But if some change in the earth’s crust (地壳) releases the pressure, the rock melts. Then the hot, liquid rock can move up toward the surface.
When the melted rock works its way close to the earth’s crust, a volcano may be formed. The melted rock often contains steam and other gases under great pressure. If the rock above gives way, the pressure is released.
Then the sudden expansion of the gases causes explosions. These blow the melted rock into pieces of different sizes and shoot them high in the air. Here they cool and harden into volcanic ash and cinders (煤灰,余烬). Some of this material falls around the hole made in the earth’s surface. The melted rock may keep on rising and pour out as lava (熔岩,火山岩). In this way, volcanic ash, cinders, and lava build up the cone-shaped (圆锥形的) mountains that we call volcanoes.
If the temperature at the earth’s surface is 20 F. , the temperature in a coal mine 500 feet below the surface would, in degrees, be______.
选项
A、30
B、40
C、120
D、500
答案
A
解析
本题是一道根据文章具体细节推断类题。问如果地球表面的温度是20华氏度,那么在地球表面以下500英尺的矿井里的温度是多少。文章第二段指出,每向下挖50英尺,温度就升高1华氏度,假设地球表面的温度是20华氏度,那么500英尺深的煤矿下的温度应是20+500÷50=30华氏度。因此,本题的正确答案应是A。
转载请注明原文地址:https://kaotiyun.com/show/p9PO777K
0
在职攻硕英语联考
相关试题推荐
Youaretowriteinnolessthan120wordsaboutthetitle"OnSpringFestivalGala".Youshouldbaseyourcompositionontheou
"WithtwofriendsIstartedajourneytoGreece,themosthorrendousofalljourneys.Ithadallthedetailsofanightmare:bar
Althoughtheculturalpatternofthecommunityaffectsearlyupbringingofachildinthehome,itis______nottheonlyfactor.
Itwasduringthemorningrushhour______thebombexploded.
Weallenjoyourfreedomofchoiceanddonotliketoseeit______whenitiswithinthelegalandmoralboundariesofsociety.
Ofalltheareasoflearning,themostimportantisthedevelopmentofattitudes.Emotionalreactionsaswellaslogicalthought
AdamSmithwasthefounderofeconomicsasadistinctfieldofstudy.Hewroteonlyonebookonthesubject—TheWealthofNati
Thoughsomepeoplehavesuggestedthatwomenshouldreturntohouseworkinordertoleavemorejobsformen,theideahasbeenr
随机试题
吾尝三战三走,鲍叔不以我为怯,知我有老母也。走:
A.压力蒸汽阀B.煮沸法C.火烧法D.药液浸泡法E.甲醛蒸汽熏蒸法在条件恶劣的情况下金属器械的消毒方法可用()
在某政府投资项目的招标人于2016年8月1日向中标人发出了中标通知书,双方于2016年8月25日签订了施工合同。根据相关法律规定,招标人应在()前向有关部门提交招标投标情况的书面报告。
下列各项中,不属于会计财务报表内容的是()。
苏联教育家()曾担任帕夫雷什中学的校长
试论资本市场的含义与功能。
某投资组合有A、B两种证券,其期望投资报酬率分别为10%和6%,投资报酬率的标准差分别为8%和10%,A、B两种证券的投资比重各为50%,当A、B证券投资报酬率的相关系数为-1时,该投资组合投资报酬率的标准差为()。
将用极坐标形式坐标为()。
Clothes,decorations,physique,hairandfacial(1)_____giveagreatdealofinformationaboutus.Forinstance,wewearclothe
Thedaywasbreakingandpeoplebegantogotoworksothemurdererwasunableto______ofthebody.
最新回复
(
0
)