首页
登录
职称英语
[originaltext] You can tell the age of a tree by counting its rings. But the
[originaltext] You can tell the age of a tree by counting its rings. But the
游客
2023-07-04
117
管理
问题
You can tell the age of a tree by counting its rings. But these records of a tree’s life really say a lot more.[16]Scientists are using tree rings to learn what’s been happening on the sun’s surface for the last 10,000 years. Each ring represents a year of growth. As the tree grows, it adds its layer to its trunk, taking up chemical elements from the air. By looking at the elements in the rings from a given year, scientists can tell what elements were in the air that year. Dr. Stevenson is analysing one element, carbon 14 in rings from both living and dead trees. Some of the rings go back almost 10,000 years to the end of the Ice Age.[17]When Stevenson followed the carbon 14 trail back in time he found carbon 14 levels change with the intensity of solar burning.[18]You see the sun has cycles. Sometimes it burns fiercely. At 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. And 10,000 years of tree rings show that the carbon 14 level rises and falls about every 420 years. But scientists concluded that solar wind activity must follow the same cycle.
16. What’s the purpose of the scientists in studying tree rings?
17. What affects the amount of carbon 14 on Earth?
18. What do we learn from the passage about solar wind activity?
选项
A、To examine the chemical elements in the Ice Age.
B、To look into the pattern of solar wind activity.
C、To analyse the composition of different trees.
D、To find out the origin of carbon 14 on Earth.
答案
B
解析
细节题。短文开头明确提到,科学家正在利用树的年轮来研究太阳表面在过去一万年的变化(what’s been happening on the sun’s surface),后面又说,通过研究树的年轮可以了解空气中碳14的含量,进而了解太阳风活动密度(the intensity of solar winds),由此可知科学家研究树的年轮是为了了解太阳风的活动频率,故答案为B)。
转载请注明原文地址:https://tihaiku.com/zcyy/2808335.html
相关试题推荐
[originaltext]AmandaLaMunyonlivesinOklahoma.Sheis14yearsold.She
[originaltext]Theinjurytothebraincausedbyablowhappenswhenthebra
[originaltext]Theinjurytothebraincausedbyablowhappenswhenthebra
[originaltext]Theinjurytothebraincausedbyablowhappenswhenthebra
[originaltext]Beforerefrigeratorswereinvented,thenextbestthingwasa
[originaltext]Beforerefrigeratorswereinvented,thenextbestthingwasa
[originaltext]Beforerefrigeratorswereinvented,thenextbestthingwasa
[originaltext]W:WilliamEdward?Isthatyou?Ican’tbelieveit.It’sbeensuc
[originaltext]W:WilliamEdward?Isthatyou?Ican’tbelieveit.It’sbeensuc
[originaltext]M:DoyourememberthemovieItoldyouthedaybefore?Allthet
随机试题
[originaltext]W:SoGreg,youarequiteaworldtravelerIhear.M:Um,yeah,I
[originaltext]M:Iseeyouandyourfriendshavebeendecoratingthedormitory.
BonAppetiteA)Wealllovethefoodwegrowupo
ThefearofFridaythe13thstemsfromtwoseparatefears--thefearofthen
关于黄体发育不全,下列哪项错误A.孕激素水平不够,子宫内膜分泌反应不良 B.月
胸痛发作已10h,疑为急性心肌梗死,实验室检查优先推荐的方案为A.仅需测定CK-
《变电检测管理规定第44分册接地引下线导通测试细则》:接地引下线导通测试试验步骤
甲状腺肿块活检,镜下见肿瘤细胞呈滤泡状生长,细胞核呈典型毛玻璃样改变,核重叠,有
()的客户一般是具有一定的资产基础、一定的知识水平和风险承受能力较高的人士,他
关于小儿骨骼发育的描述,正确的是( )。A.颅缝一般闭合的年龄是生后2个月
最新回复
(
0
)