网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)

Questions 21 to 25 are based on the following passage. Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly. A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining. In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States. In a study published in the journal Ambio, scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline. Many scientists had believed that the lead would stay in soil and snow for a longer period. The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected. Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统) respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute. The study published in the journal Nature indicates that ()

  • A、the Clean Air Act has not produced the desired results
  • B、lead deposits in arctic snow are on the increase
  • C、lead will stay in soil and snow longer than expected
  • D、the US is the major source of lead pollution in arctic snow

参考答案

更多 “Questions 21 to 25 are based on the following passage. Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly. A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining. In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States. In a study published in the journal Ambio, scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline. Many scientists had believed that the lead would stay in soil and snow for a longer period. The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected. Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统) respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute. The study published in the journal Nature indicates that ()A、the Clean Air Act has not produced the desired resultsB、lead deposits in arctic snow are on the increaseC、lead will stay in soil and snow longer than expectedD、the US is the major source of lead pollution in arctic snow” 相关考题
考题 在 X.25 网络中, (21) 是网络层协议。(21)A. LAP-BB. X.21C. X.25PLPD. MHS

考题 The reason why lesson six skips the puzzle questions is that they are associated with the expertise based on the content of a particular subject which is likely irrelevant to a layman.()

考题 25.In studying ,we must always ask "whys" in order to ________.A. understand the book wellB. get some questions to ask our teachersC. do with the new wordsD. write down the questions

考题 Originally introduced by Netscape Communications,(21)are a general mechanism which HTTP Server side applications, such as CGI(22), can use to both store and retrieve information on the HTTP(23)side of the connection. Basically, Cookies can be used to compensate for the(24)nature of HTTP. The addition of a simple, persistent, client-side state significantly extends the capabilities of WWW-based(25).A.BrowsersB.CookiesC.ConnectionsD.Scripts

考题 DOM is a platform-and language-(21)API that allows programs and scripts to dynamically access and update the content, structure and style. of WWW documents (currently ,definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented(22). DOM is a(23)-based AP1 to documents, which requires the whole document to be represented in(24)while processing it. A simpler alternative to DOM is the event-based SAX, which can be used to process very large(25)documents that do not fit info the memory available for processing.A.specificB.neutralC.containedD.related

考题 对一组数据(84,47,25,15,21)排序,数据的排列次序在排序过程中的变化为(1)84 47 25 15 21(2)15 47 25 84 21(3)15 21 25 84 47(4)15 21 25 47 84,则采用的排序是(36)。A.选择B.冒泡C.快速D.插入

考题 Which of the following types of questions are mostly used for checking literal comprehension of the text? A. Display questions. B. Rhetorical questions. C. Evaluation questions. D. Referential questions.

考题 Which of the following types of questions can least elicit students′ ideas A.Display questions. B.Divergent questions. C.Open questions. D.Evaluation questions.

考题 Which of the following types of questions are mostly used for checking literal comprehensionof the test A.Display questions. B.Rhetorical questions. C.Evaluation questions. D.Referential questions.

考题 对下列关键字序列用快速排序法进行排序时,速度最快的是()。A.{21,25,5,17,9,23,30} B.{25,23,30,17,21,5,9} C.{21,9,17,30,25,23,5} D.{5,9,17,21,23,25,30}

考题 ftp和telnet的端口号分别是()A、21;23B、23;25C、25;21D、23;21

考题 对下列关键字序列用快速排序法进行排序时,速度最快的情形是()A、{21、25、5、17、9、23、30}B、{25、23、30、17、21、5、9}C、{21、9、17、30、25、23、5}D、{5、9、17、21、23、25、30}

考题 On the serial interface of a router, an inbound access list is configured to deny all traffic from UDP and TCP ports 21, 23, and 25. All other traffic is permitted. Based on this information, which types of traffic will be allowed through this interface?()A、SMTPB、DNSC、FTPD、TelnetE、HTTPF、POP3

考题 除()客车外,其他客车均禁止通过驼峰。A、21、22型B、21、25型C、22、25型D、21、22、25型

考题 交换局、数据机房、基站空调温度设置值按顺序分别为()A、21℃、23℃、25℃B、23℃、23℃、25℃C、25℃、23℃、25℃D、23℃、21℃、25℃

考题 A customer asked a consultant to create the infrastructure for an application.  The application is designed to charge customers for conferencing services based on usage.  To determine if a Storage Area Network (SAN) is the best storage solution, which of the following questions is most appropriate?()A、Will the application require a database?B、Which operating system does the application require?C、Will the data need to be backed up in real time?D、Does the application share data among the servers?

考题 单选题INTERVIEW 1  Questions 1 to 5 are based on an interview. At the end of the interview you will be given 10 seconds to answer each of the following five questions.   Now listen to the interview. Juliet became a taxi driver becauseA she owned a car.B she drove well.C she liked drivers’ uniforms.D it was her childhood dream.

考题 判断题There are questions with regard to the usefulness of the computer-based technologies for they have never been tested before.A 对B 错

考题 单选题对下列关键字序列用快速排序法进行排序时,速度最快的情形是()A {21、25、5、17、9、23、30}B {25、23、30、17、21、5、9}C {21、9、17、30、25、23、5}D {5、9、17、21、23、25、30}

考题 多选题On the serial interface of a router, an inbound access list is configured to deny all traffic from UDP and TCP ports 21, 23, and 25. All other traffic is permitted. Based on this information, which types of traffic will be allowed through this interface?()ASMTPBDNSCFTPDTelnetEHTTPFPOP3

考题 单选题NEWS BROADCAST 3  Questions 9 and 10 are based on the following news. At the end of the news item, you will be given 20 seconds to answer the questions.  Now listen to the news.The process of rescuing trapped miners is slow due toA the difficulties of getting down into the coal mine.B the great casualties of the mining accident.C the risk of catching infectious disease.D the continuous blasts inside the coal mine.

考题 问答题Practice 1Directions: In this part of the test, you will answer three questions based on the information provided. You will have 30 seconds to read the information before the questions begin. For each question, begin responding immediately after you hear a beep. No additional preparation time is provided. You will have 15 seconds to respond to Questions 1 and 2 and 30 seconds to respond to Question 3.Practice 1  Question 1: How much are tickets?  Question 2: I heard Time Against Time was coming out. Is it playing there yet?  Question 3: I might not be able to go to the theater until 7:30. Which movies are playing at around that time?

考题 单选题NEWS BROADCAST 1  Questions 6 and 7 are based on the following news. At the end of the news item, you will be given 20 seconds to answer the questions.   Now listen to the news. Greek bonds is downgraded as junk status becauseA share prices in New York and London fell by over 2%.B the Greek debt crisis could spread to other countries.C the bond holders may not be repaid in full.D Greek bonds could trigger a financial crisis.

考题 单选题除()客车外,其他客车均禁止通过驼峰。A 21、22型B 21、25型C 22、25型D 21、22、25型

考题 单选题Which of the following types of questions can least elicit students' ideas?A Display questions.B Divergent questions.C Open questions.D Evaluation questions.

考题 单选题INTERVIEW2  In this section you will hear everything ONCE ONLY. Listen carefully and then answer the questions that follow. Mark the best answer to each question on ANSWER SHEET TWO.   Questions 1 to 5 are based on an interview. At the end of the interview you will be given 10 seconds to answer each of the following five questions.   Now listen to the interview. Which of the following is NOT Vera’s tip for finding a new job?A Narrow down the scope of search.B Decide what you value the most.C Do some soul searching.D Make your resume distinctive.

考题 单选题NEWS BROADCAST 4  Questions 8 and 9 are based on the following news. At the end of the news item, you will be given 20 seconds to answer the questions.   Now listen to the news. Top officials of several U. S. intelligence agencies believe thatA the country’s security is not good enough.B the U. S. will face an attempted terrorist threat.C there will be no actual attack in the U.S.D an anti-terrorism practice will be held in the following months.

考题 单选题NEWS BROADCAST 5  Questions 7 and 8 are based on the following news. At the end of the news item. you will be given 20 seconds to answer the questions.  Now listen to the news.Which manufacturer’s sales dropped the most in percentage in June?A Chrysler.B Daimler Chrysler.C General Motors.D Ford.