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
A、The lifecycle of trees. B、The number of trees. C、The intensity of solar burning. D、The quality of air. C细节题。根据短文里提到太阳燃烧得越热烈,太阳
A、The lifecycle of trees. B、The number of trees. C、The intensity of solar burning. D、The quality of air. C细节题。根据短文里提到太阳燃烧得越热烈,太阳
admin
2013-11-21
39
问题
You can tell the age of a tree by counting its rings but these records of trees’ life really say a lot more. Scientists are using tree rings to learn what’s being happening on the sun’s surface for the last ten thousand years. Each ring represents a year of growth. As the tree grows, it adds a layer to its trunk taking up chemical elements from the air. By looking up the elements in the rings for a given year, scientists can tell what elements were in the air that year. Doctors Stevenson is analyzing one element — carbon-14 in ring from both living and dead trees. Some of the rings go back almost ten thousand years to the end of the Ice Age. When Stevenson followed the carbon-14 trail back in time, he found carbon-14 levels change with the intensity of solar burning. You see the sun has cycles. Sometimes it burns fiercely and other times it’s relatively calm. During the sun’s violent periods, it throws off charged particles in fast moving strings called solar winds. The particles interfere with the formation of carbon-14 on earth. When there’s more solar wind activity, less carbon-14 is produced. Ten thousand years of tree rings show that the carbon-14 level rises and falls about every 420 years. The scientists concluded that the solar wind activity must follow the same cycle.
Questions 20 to 22 are based on the passage you have just heard.
20. What do the scientists want to learn by using tree rings according to the passage?
21. What affects the amount of carbon-14 on earth?
22. What do we learn from the passage about the solar wind activity?
选项
A、The lifecycle of trees.
B、The number of trees.
C、The intensity of solar burning.
D、The quality of air.
答案
C
解析
细节题。根据短文里提到太阳燃烧得越热烈,太阳风的活动就越频繁,碳14的数量就产生得越少。
转载请注明原文地址:https://kaotiyun.com/show/GVS7777K
0
大学英语四级
相关试题推荐
A、Hisadvisor.B、Histeacher.C、Hispartner.D、Hisboss.DW:Thisisthethirdtimeyou’vebeenlatethisweek,Robert.You’llh
Whensheinterviewsteachingcandidates,principalLaurelTellerfavorstheoneswhoshowtheyhaveaheartforchildren,notju
Abalanceddietprovidesanadequateintakeofnutrientsformaintenanceofthebodyandthereforegoodhealth.Adietcaneasil
TheAustralianPartiesTheAustralianpoliticalsceneisdominatedbytwomajorpartiesthathavequitedifferentpolitical
A、Hisrivalsandteammates.B、Hiscoachandteammates.C、Hisfamilyandhisteammates.D、Hiscountrymenandhisfamily.A
A、Walkthedog.B、Cleanthehouse.C、Gotothedoctor’s.D、Finishherassignment.B细节题。四个选项都是动词短语,问题可能是what引导的。对话中男士邀请女士星期六看电影或湖
Theageatwhichkidsfirstfallvictimtobullying(欺侮)couldinfluencehowstronglytheyareaffected,suggestsanewstudy.And
It’spartofthenewyearritual—anannualattempttostartafreshandturnoveranewleaf.Butmakingresolutionsisanearpo
Peoplewhoaretoohappydieyoungerthantheirmoredownbeatpeers,claimsnewresearch.Astudywhichfollowedchildrenfr
Notlongago,manypeoplebelievedthatbabiesonlywantedfoodandtobekeptwarmanddry.Somepeople(1)______babieswerenot
随机试题
A.黄连、黄芩、黄柏B.黄芩、黄连、栀子C.黄芩、连翘、甘草D.黄芩、黄柏、栀子黄连解毒汤与清瘟败毒饮中均含有的药物是
下列关于整合营销的重点说法错误的是:()。
铸石管的特点是( ),多用于承受各种强烈磨损和强酸和碱腐蚀的地方。
【背景资料】某公司承建一座城市快速路跨河桥梁,该桥由主桥、南引桥和北引桥组成,分东、西双幅分离式结构,主桥中跨下为通航航道,施工期间航道不中断。主桥的上部结构采用三跨式预应力混凝土连续刚构,跨径组合为75m+120m+75m;南、北引桥的上部结构
信用证关于货物的描述为“bluecottonwears”,发票显示为“coloredcottonwears”是可以的。()
受害人对于损害的发生也有过错的,( )侵害人的民事责任。
北京市政府最近出台了一系列与残疾人相关的措施,如举办再就业培训、残疾人个人所得税减免、对残疾人制定了小额贷款和贴息的办法等。这些措施都极大地促进了残疾人的就业,保障了残疾人的()
接收110报警,突发事件和治安灾害事故的现场指挥、处置与救助工作属于()。
调查表明,使得大学生学习成绩下降的一个重要因素是:很多大学生玩网络游戏。为了提高大学生的学习成绩,学校作出决定:禁止在校园网上玩网络游戏。以下哪项最能对学校的决定进行质疑?
查询第一作者为“张三”的所有书名及出版社,正确的SQL语句是()。
最新回复
(
0
)