bitfinex

              手机APP下载

              bitfinex www.bbfst.com

              您现在的位置: bitfinex > SAT > SAT每日一题 > 正文

              SAT官方每日一题附答案和解析[阅读](2020年2月18日)

              来源:可可英语 编辑:max ?  VIP免费外教试听课 |  可可官方微信:ikekenet


              Critical Reading>Select an Answer

              Four billion years ago, Earth's continents began taking shape. Scientists long held that this process unfolded gradually. It would have taken millions of years for granite, the primary component of the continental crust, to form in the mantle and migrate to the upper crust, they reasoned. But new research suggests that these events may have proceeded at rather a different pace. According to a report published in the journal Nature, the emergence of granite occurred by way of swift, dynamic and possibly catastrophic events lasting from 1,000 to 100,000 years.

              Geologist Alexander Cruden of the University of Toronto and his colleagues turned to experimental studies—melting rock samples, for example—to explore how granite magma forms and how fast it can move. Their results proved surprising. "In the past we thought that granite magma, which cools and crystallizes to form very large granite intrusions, moved up through kilometers of crust as large, solid blobs at rates of about a meter per year," Cruden says. "But we've found that magma actually has quite low viscosity and is relatively runny. Because it is runny, it is able to channel its way from the mantle and lower crust through fractures and cracks that are as small as one meter thick."

              According to this model, granite intrusions in Greenland or the Canadian Shield, depending on their size, would have taken only thousands of years to form, which is extraordinarily fast from a geological point of view, Cruden notes.

              The passage indicates that Cruden and his team made use of primarily what kind of research in their study?

              (A) Hands-on experimentation
              (B) Theoretical computer modeling
              (C) Synthesis of scholarly literature
              (D) Analysis of case studies

              重点单词   查看全部解释    
              scholarly ['skɔləli]

              想一想再看

              adj. 学究气的,学者派头的 名词scholar的形容

               
              channel ['tʃænl]

              想一想再看

              n. 通道,频道,(消息)渠道,海峡,方法
              v

              联想记忆
              primary ['praiməri]

              想一想再看

              adj. 主要的,初期的,根本的,初等教育的

              联想记忆
              synthesis ['sinθisis]

              想一想再看

              n. 合成,综合,推理

              联想记忆
              thickness ['θiknis]

              想一想再看

              n. 厚度,一层,含混不清

               
              dynamic [dai'næmik]

              想一想再看

              adj. 动态的,动力的,有活力的
              n. 动力

               
              emergence [i'mə:dʒəns]

              想一想再看

              n. 出现,浮现,露出

              联想记忆
              shield ['ʃi:ld]

              想一想再看

              n. 盾,防卫物,盾状物
              vt. ?;?,遮蔽

               
              viscosity [vis'kɔsiti]

              想一想再看

              n. 粘度,粘性

               
              theoretical [θiə'retikəl]

              想一想再看

              adj. 理论上的

               
              ?
              发布评论我来说2句

                最新文章

                可可英语官方微信(微信号:ikekenet)

                每天向大家推送短小精悍的英语学习资料.

                添加方式1.扫描上方可可官方微信二维码。
                添加方式2.搜索微信号ikekenet添加即可。

                百度|中国纪委国家监委网站|北京纪检监察网|bitfinex注册 | bitfinex平台 | www.baidu.com-百度百科|

                健康遊戲忠告:抵制不良遊戲拒絕盜版遊戲注意自我保護謹防受騙上當適度遊戲益腦沉迷遊戲傷身合理安排時間享受健康生活

                備案號:皖B2-2334451本站www.bbfst.com所有