Question

19．Carbon monoxide（一氧化碳） poisoning kills and injures many people and animals around the world．The gas has been a problem since people first began burning fuels to cook food or to create heat．It is a problem in all parts of the world that experience cold weather．
Carbon monoxide is called the silent killer because people do not know it is in the air．The gas has no color．It has no taste．It has no smell．It does not cause burning eyes．And it does not cause people to cough．But it is very deadly．It robs the body of its ability to use oxygen．
Carbon monoxide decreases the ability of the blood to carry oxygen to body tissues．It does this by linking with the blood．When the gas links with the blood，the blood is no longer able to carry oxygen to the tissues that need it．
Damage to the body can begin very guickly from large amounts of carbon monoxide．How quickly this happens depends on the length of time a perosn is breathing the gas and the amount of the gas he or she breathes in．
Carbon monoxide poisoning has waming sings．But people have to be awake to recognize them．Small amounts of the gas will cause a person's head to hurt．He or she may beginto feel tired．The person may have trouble thinking clearly．Peole develop severe head pains as the amount of gas continues to erter their blood．They will begin to feel very tired and sleepy．They may have terribe stomach pains．
Medical experts say carbon monoxide affects people differently．For example，a small child will experience health problems or die much quicker than an adult will．The general heath of person or his or her age can also be important．An older adult with health problems may suffer the effects of carbon monoxide more quickly than a younger person with no health problems．People with heart disease may suffer chest pains．They may begin to have trouble breathing．
 
31．Why is carbon monoxide called the silent killer？B
A．Because it tastes and smells good．
B．Because it is not easily noticed．
C．Because it kills and injures people．
D．Because it always harms people．
32．How does carbon monoxide harm people？D
A．It makes people's blood unable to move．
B．It decreases the amount of blood in the body．
C．It makes body tissues full of blood．
D．It makes the blood less able to carry oxygen．
33．When people breathe in small amounts of carbon monoxide，they mayA．
A．feel a little dizzy             B．suffer a severe headache
C．go around in the room           D．have a terrible stomachache
34．Which of the following about carbon monoxide poisoning is true？C
A．Adults are affected more seriously than children．
B．Young people are more severely affected than old people．
C．People in poor health may have more severe consequences．
D．People with heart problem only suffer from chest pains．
35．The purpose of the passage is toD．
A．warn people not to burn fuels to keep warm in the winter．
B．list the damages that carbon monoxide brings to people．
C．give advice on how to avoid carbon monoxide poisoning．
D．introduce some knowledge about carbon monoxide poisoning．

Answer 1

分析 本文属于说明文阅读，作者通过这篇文章主要向我们描述了一氧化碳的特性，一氧化碳中毒的原理及中毒后人体的反应等，提醒读者一定要谨防一氧化碳中毒．

解答 31．B．细节理解题．题干关键词为"the silent killer"．由文章第二段中的"The gas has no color．It has no taste．It has no smell．It does not cause burning eyes．And it does not cause people to cough．"可以看出，一氧化碳无色、无味、不刺激眼睛、也不会让人咳嗽，也就是说它不容易被人发觉．故选B．
32．D．细节理解题．由第三段第一句"Carbon monoxide decreases the ability of the blood to carry oxygen to body tissues．"可以看出，一氧化碳伤害人体的方式是：降低血液携带氧气的能力；故选D．
33．A．细节理解题．倒数第二段向我们描述了人体吸入一氧化碳后的反应：吸入少量时，会头疼，感觉劳累，恶心，房子似乎开始转动，不能清晰地思考．A项所说的"feel a little dizzy"对应"The room may appear to be turning around．"；故选A．
34．C．细节理解题．最后一段讲述了不同的人吸入一氧化碳后的不同反应，老人及身体健康状况欠佳的人所受的影响会更大．注意，D项干扰性最大，但是"suffer from chest pains"只是患有心脏方面疾病的人一氧化碳中毒后的症状之一，而不是唯一的症状，其症状还包括"terrible stomach pains"；故选C．
35．D．写作目的题．从全文内容可知，文章向我们介绍了一氧化碳的特性，一氧化碳中毒的原理及中毒后人体的反应等，故D项是文章的写作目的；故选D．

点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．