题目
Can electricity cause cancer？ In a society that literally runs on electric power， the very idea seems ridiculous． But for more than a decade， a growing band of scientists and journalists has pointed to studies that seem to link exposure to electromagnetic fields（电磁场） with increased risk of leukemia（白血病） and other malignancies． The implications are unsettling， to say the least， since everyone comes into contact with such fields， which are generated by everything electrical， from power lines and antennas to personal computers and micro-wave ovens． Because evidence on the subject is inconclusive and often contradictory， it has been hard to decide whether concern about the health effects of electricity is reasonable --- or a kind of oversensitivity． Now the alarmists have gained some qualified support from the U．S． Environmental Protection Agency． In the executive summary of a new scientific review， released in draft form late last week， the EPA has put forward what amounts to the most serious government warning to date． The agency tentatively concludes that scientific evidence "suggests a causal（因果关系的） link" between extremely low-frequency electromagnetic fields （ELF） --- those having very longwave-lengths ---and leukemia， lymphoma and brain cancer． While the report falls short of classifying ELF fields as probable carcinogens（致癌物）， it does identify the common 60-hertz magnetic field as "a possible， but not proven， cause of cancer in humans．" The report is no reason to panic --- or even to lost sleep． If there is a cancer risk， it is a small one． The evidence is still so controversial that the draft stirred a great deal of debate within the Bush Administration， and the EPA released it over strong objections from the Pentagon and the White House． But now no one can deny that the issue must be taken seriously and that much more research is needed． At the heart of the debate is a simple and well-understood physical phenomenon： When an electric current passes through a wire， it generates an electromagnetic field that exerts forces on surrounding objects， For many years， scientists dismissed any suggestion that such forces might be harmful， primarily because they are so extraordinarily weak． The ELF magnetic field generated by a video terminal measures only a few milligauss， or about one-hundredth the strength of the earth's own magnetic field． The electric fields surrounding a power line can be as high as 10kilovolts per meter， but the corresponding field induced in human cells will be only about 1millivolt per meter． This is far less than the electric fields that the cells themselves generate． How could such minuscule（极小的） forces pose a health danger？ The consensus used to be that they could not， and for decades scientists concentrated on more powerful kinds of radiation， like X-rays， that pack sufficient wallop to knock electrons out of the molecules that make up the human body． Such "ionizing" radiations have been clearly linked to increased cancer risks and there are regulations to control emissions． But epidemiological（流行病学的） studies， which find statistical associations between sets of data， do not prove cause and effect． Though there is a body of laboratory work showing that exposure to ELF fields can have biological effects on animal tissues， a mechanism by which those effects could lead to cancerous growths has never been found． The Pentagon is far from persuaded． In a blistering 33-page critique of the EPA report， Air Force scientists charge its authors with having "biased（使倾向于） the entire document" toward proving a link． "Our reviewers are convinced that there is no suggestion that （electromagnetic fields） present in the environment induce or promote cancer，" the Air Force concludes． "It is astonishing that the EPA would approve the release of this report．" Then Pentagon's concern is understandable． There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment， from huge ground-based radar towers to the defense systems built into every warship and plane．（1）The main idea of this passage is ____ ．A． studies on the cause of cancerB． controversial view-points in the cause of cancerC． the relationship between electricity and cancer．D． different ideas about the effect of electricity on caner．（2）Why did the Pentagon and White House object to the release of the report？ Because ____ ．A． it may stir a great deal of debate among the Bush Administration．B． every unit of the modern military has depended on the heavy use of some kind of electronic equipment．C． the Pentagon's concern was understandable．D． they had different arguments．（3）It can be inferred from physical phenomenon ____ ．A． the force of the electromagnetic field is too weak to be harmful．B． the force of the electromagnetic field is weaker than the electric field that the cells generate．C． electromagnetic field may affect health．D． only more powerful radiation can knock electron out of human body．（4）What do you think ordinary citizens may do after reading the different arguments？ ____ A． They are indifferent．B． They are worried very much．C． The may exercise cautious avoidance．D． They are shocked．
Can electricity cause cancer？ In a society that literally runs on electric power， the very idea seems ridiculous． But for more than a decade， a growing band of scientists and journalists has pointed to studies that seem to link exposure to electromagnetic fields（电磁场） with increased risk of leukemia（白血病） and other malignancies． The implications are unsettling， to say the least， since everyone comes into contact with such fields， which are generated by everything electrical， from power lines and antennas to personal computers and micro-wave ovens． Because evidence on the subject is inconclusive and often contradictory， it has been hard to decide whether concern about the health effects of electricity is reasonable --- or a kind of oversensitivity．
Now the alarmists have gained some qualified support from the U．S． Environmental Protection Agency． In the executive summary of a new scientific review， released in draft form late last week， the EPA has put forward what amounts to the most serious government warning to date． The agency tentatively concludes that scientific evidence "suggests a causal（因果关系的） link" between extremely low-frequency electromagnetic fields （ELF） --- those having very longwave-lengths ---and leukemia， lymphoma and brain cancer． While the report falls short of classifying ELF fields as probable carcinogens（致癌物）， it does identify the common 60-hertz magnetic field as "a possible， but not proven， cause of cancer in humans．"
The report is no reason to panic --- or even to lost sleep． If there is a cancer risk， it is a small one． The evidence is still so controversial that the draft stirred a great deal of debate within the Bush Administration， and the EPA released it over strong objections from the Pentagon and the White House． But now no one can deny that the issue must be taken seriously and that much more research is needed．
At the heart of the debate is a simple and well-understood physical phenomenon： When an electric current passes through a wire， it generates an electromagnetic field that exerts forces on surrounding objects， For many years， scientists dismissed any suggestion that such forces might be harmful， primarily because they are so extraordinarily weak． The ELF magnetic field generated by a video terminal measures only a few milligauss， or about one-hundredth the strength of the earth's own magnetic field． The electric fields surrounding a power line can be as high as 10kilovolts per meter， but the corresponding field induced in human cells will be only about 1millivolt per meter． This is far less than the electric fields that the cells themselves generate．
How could such minuscule（极小的） forces pose a health danger？ The consensus used to be that they could not， and for decades scientists concentrated on more powerful kinds of radiation， like X-rays， that pack sufficient wallop to knock electrons out of the molecules that make up the human body． Such "ionizing" radiations have been clearly linked to increased cancer risks and there are regulations to control emissions．
But epidemiological（流行病学的） studies， which find statistical associations between sets of data， do not prove cause and effect． Though there is a body of laboratory work showing that exposure to ELF fields can have biological effects on animal tissues， a mechanism by which those effects could lead to cancerous growths has never been found．
The Pentagon is far from persuaded． In a blistering 33-page critique of the EPA report， Air Force scientists charge its authors with having "biased（使倾向于） the entire document" toward proving a link． "Our reviewers are convinced that there is no suggestion that （electromagnetic fields） present in the environment induce or promote cancer，" the Air Force concludes． "It is astonishing that the EPA would approve the release of this report．" Then Pentagon's concern is understandable． There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment， from huge ground-based radar towers to the defense systems built into every warship and plane．
（1）The main idea of this passage is ____ ．
A． studies on the cause of cancer
B． controversial view-points in the cause of cancer
C． the relationship between electricity and cancer．
D． different ideas about the effect of electricity on caner．
（2）Why did the Pentagon and White House object to the release of the report？ Because ____ ．
A． it may stir a great deal of debate among the Bush Administration．
B． every unit of the modern military has depended on the heavy use of some kind of electronic equipment．
C． the Pentagon's concern was understandable．
D． they had different arguments．
（3）It can be inferred from physical phenomenon ____ ．
A． the force of the electromagnetic field is too weak to be harmful．
B． the force of the electromagnetic field is weaker than the electric field that the cells generate．
C． electromagnetic field may affect health．
D． only more powerful radiation can knock electron out of human body．
（4）What do you think ordinary citizens may do after reading the different arguments？ ____
A． They are indifferent．
B． They are worried very much．
C． The may exercise cautious avoidance．
D． They are shocked．
Now the alarmists have gained some qualified support from the U．S． Environmental Protection Agency． In the executive summary of a new scientific review， released in draft form late last week， the EPA has put forward what amounts to the most serious government warning to date． The agency tentatively concludes that scientific evidence "suggests a causal（因果关系的） link" between extremely low-frequency electromagnetic fields （ELF） --- those having very longwave-lengths ---and leukemia， lymphoma and brain cancer． While the report falls short of classifying ELF fields as probable carcinogens（致癌物）， it does identify the common 60-hertz magnetic field as "a possible， but not proven， cause of cancer in humans．"
The report is no reason to panic --- or even to lost sleep． If there is a cancer risk， it is a small one． The evidence is still so controversial that the draft stirred a great deal of debate within the Bush Administration， and the EPA released it over strong objections from the Pentagon and the White House． But now no one can deny that the issue must be taken seriously and that much more research is needed．
At the heart of the debate is a simple and well-understood physical phenomenon： When an electric current passes through a wire， it generates an electromagnetic field that exerts forces on surrounding objects， For many years， scientists dismissed any suggestion that such forces might be harmful， primarily because they are so extraordinarily weak． The ELF magnetic field generated by a video terminal measures only a few milligauss， or about one-hundredth the strength of the earth's own magnetic field． The electric fields surrounding a power line can be as high as 10kilovolts per meter， but the corresponding field induced in human cells will be only about 1millivolt per meter． This is far less than the electric fields that the cells themselves generate．
How could such minuscule（极小的） forces pose a health danger？ The consensus used to be that they could not， and for decades scientists concentrated on more powerful kinds of radiation， like X-rays， that pack sufficient wallop to knock electrons out of the molecules that make up the human body． Such "ionizing" radiations have been clearly linked to increased cancer risks and there are regulations to control emissions．
But epidemiological（流行病学的） studies， which find statistical associations between sets of data， do not prove cause and effect． Though there is a body of laboratory work showing that exposure to ELF fields can have biological effects on animal tissues， a mechanism by which those effects could lead to cancerous growths has never been found．
The Pentagon is far from persuaded． In a blistering 33-page critique of the EPA report， Air Force scientists charge its authors with having "biased（使倾向于） the entire document" toward proving a link． "Our reviewers are convinced that there is no suggestion that （electromagnetic fields） present in the environment induce or promote cancer，" the Air Force concludes． "It is astonishing that the EPA would approve the release of this report．" Then Pentagon's concern is understandable． There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment， from huge ground-based radar towers to the defense systems built into every warship and plane．
（1）The main idea of this passage is ____ ．
A． studies on the cause of cancer
B． controversial view-points in the cause of cancer
C． the relationship between electricity and cancer．
D． different ideas about the effect of electricity on caner．
（2）Why did the Pentagon and White House object to the release of the report？ Because ____ ．
A． it may stir a great deal of debate among the Bush Administration．
B． every unit of the modern military has depended on the heavy use of some kind of electronic equipment．
C． the Pentagon's concern was understandable．
D． they had different arguments．
（3）It can be inferred from physical phenomenon ____ ．
A． the force of the electromagnetic field is too weak to be harmful．
B． the force of the electromagnetic field is weaker than the electric field that the cells generate．
C． electromagnetic field may affect health．
D． only more powerful radiation can knock electron out of human body．
（4）What do you think ordinary citizens may do after reading the different arguments？ ____
A． They are indifferent．
B． They are worried very much．
C． The may exercise cautious avoidance．
D． They are shocked．
题目解答
答案
1．D．细节理解题．根据第一段"Because evidence on the subject is inconclusive and often contradictory， it has been hard to decide whether concern about the health effects of electricity is reasonable．"由于关于这一问题的证据不是决定性的，而且往往相互矛盾，因此很难确定对电力对健康的影响的关注是否合理．可知这篇文章的主要观点是关于电对癌症的影响的不同观点．故选D．
2．B．推理判断题．根据最后一段"Then Pentagon's concern is understandable． There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment， from huge groundbased radar towers to the defense systems built into every warship and plane．"．那么，五角大楼的担忧是可以理解的．现代军事中几乎没有一支部队不依赖于某种电子设备的大量使用，从巨大的地面雷达塔到每艘军舰和飞机上的防御系统．"可知五角大楼和白宫反对公布这份报告因为现代军队的每一个单位都依赖于某种电子设备的大量使用．故选B．
3．A．推理判断题．根据第五段"How could such insignificant forces pose a health danger？ The consensus used to be that they could not， and for decades scientists concentrated on more powerful kinds of radiation， like Xrays，"这些微不足道的力量怎么会对健康构成威胁呢？过去的共识是，他们不能，几十年来，科学家集中在更强大的辐射，如X射线．可知从物理现象可以推断，电磁场的力太弱，不可能有害．故选A．
4．C．推理判断题．根据文章第一段 The implications are unsettling， to say the least， since everyone comes into contact with such fields， which are generated by everything electrical， from power lines and antennas to personal computers and micro-wave ovens至少可以说，这种影响是令人不安的，因为每个人都会接触到这些领域，这些领域是由电线、天线、个人电脑和微波炉等所有电气设备产生的．可知普通公民在阅读不同的论点后可能采取谨慎的回避措施；故选C
2．B．推理判断题．根据最后一段"Then Pentagon's concern is understandable． There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment， from huge groundbased radar towers to the defense systems built into every warship and plane．"．那么，五角大楼的担忧是可以理解的．现代军事中几乎没有一支部队不依赖于某种电子设备的大量使用，从巨大的地面雷达塔到每艘军舰和飞机上的防御系统．"可知五角大楼和白宫反对公布这份报告因为现代军队的每一个单位都依赖于某种电子设备的大量使用．故选B．
3．A．推理判断题．根据第五段"How could such insignificant forces pose a health danger？ The consensus used to be that they could not， and for decades scientists concentrated on more powerful kinds of radiation， like Xrays，"这些微不足道的力量怎么会对健康构成威胁呢？过去的共识是，他们不能，几十年来，科学家集中在更强大的辐射，如X射线．可知从物理现象可以推断，电磁场的力太弱，不可能有害．故选A．
4．C．推理判断题．根据文章第一段 The implications are unsettling， to say the least， since everyone comes into contact with such fields， which are generated by everything electrical， from power lines and antennas to personal computers and micro-wave ovens至少可以说，这种影响是令人不安的，因为每个人都会接触到这些领域，这些领域是由电线、天线、个人电脑和微波炉等所有电气设备产生的．可知普通公民在阅读不同的论点后可能采取谨慎的回避措施；故选C
解析
考查要点：本题主要考查学生对文章主旨的把握、细节推理能力以及对隐含信息的推断能力。文章围绕电力与癌症之间的潜在关联展开，讨论了科学界、政府机构及军事部门对此的不同态度。
解题核心思路：
- 主旨题需通篇把握文章核心矛盾点（电力是否致癌），结合选项匹配。
- 推理题需结合上下文逻辑关系，注意关键细节（如 Pentagon 的反对理由）。
- 隐含信息题需从物理现象描述中提炼作者未明说的结论（电磁场力量弱）。
- 推断行为题需结合文章整体基调（不确定性引发谨慎态度）。
第（1）题
关键点：文章首段提出“电力对健康的影响是否合理”存在争议，后文通过 EPA 报告、 Pentagon 反对等展开讨论。选项 D（不同观点）最能概括全文核心矛盾。
第（2）题
关键点：最后一段明确 Pentagon 的担忧是“现代军事依赖电子设备”，白宫反对与 Pentagon 利益相关，而非单纯“有不同观点”。
第（3）题
关键点：第五段通过“微不足道的力量”“过去共识是无害”等描述，暗示电磁场力量弱到无法造成伤害，需从反面推断。
第（4）题
关键点：文章强调“证据不充分”“需进一步研究”，普通民众面对“可能致癌但未证实”的信息，最可能采取“谨慎避免”态度。