单选题 {{B}}Passage Four{{/B}}
Now medical researchers are discovering a truism: "alcohol and tobacco do not mix." These two substances, both dangerous to health, act synergistically, each making the other more powerful and thereby causing worse damage than either would do alone.
Because of this interaction, the person who both smokes and drinks heavily may be at a greater risk of becoming ill than one who drinks like a fish, but never smokes or who smokes like a chimney, but never drinks. To get an idea of how this synergism may work, consider what happens when a smoker lights up a cigarette. With each puff he inhales at least 4,000 different chemicals. These include toxic hydrogen-cyanide, carbon monoxide and nitrogen-dioxide gases, and four dozen compounds such as benzo pyrene and radioactive polonium 210. All are known as carcinogens. Most chemical vapors in tobacco smoke get deposited in the mouth, nose, throat and lungs in a coating called tar. It is in this tar that most of the cancer--inducing potential of tobacco smoke lies. Then in a scenario typical of chronic heavy drinkers--most of whom also smoke--our smoker feels thirsty and washes down that smoke coating in his mouth and throat with whisky. The alcohol in his drink is not in itself a carcinogen, but it may act as a solvent, dissolving the tar-taped tobacco poisons, and easing the transport of carcinogens across membranes.
Our smoker continues to drink. Soon he lights another cigarette and inhales deeply. Behind his embattled lungs, meanwhile, his liver has gone on full alert to save his life. The three-pound chemical factory, which cleans most toxins from the bloodstream, reacts to alcohol as a foreign substance and metabolizes 95 percent of it into other chemicals. But in turning its energy to clearing just one-half ounce of pure alcohol--the amount in a standard drink--per hour from our drinking smoker's blood, the liver's other metabolic functions suffer a sharp decrease. Poisons from tobacco smoke that otherwise would be removed from his blood within minutes are now allowed to flood his body for hours or days, depending on how much alcohol the liver must dispose of.
The person who smokes one or two packs of cigarettes a day loses on average six to eight percent of his blood's oxygen carrying capacity. If our heavy smoker's use of alcohol has led to alcoholism, he is probably malnourished. This malnourishment compounds problems he is having with insufficient oxygen. His brain cells are dying from it.
The synergistic effect of alcohol and tobacco may deliver a powerful blow to the cardiovascular system as well as the upper respiratory tract. For those prone to hypertension who drink more than two ounces of alcohol a day, high blood pressure is common and with it the increased risk of stroke and heart attack. For hypertensives who combine smoking and drinking, the risks are even greater.
单选题 Which of the following can be the best title of this passage?
【正确答案】 A
【答案解析】这是一道主旨题。文章第一段指出:现在,医学研究人员发现了一个公认的真理——酒精和烟草不能混合使用;这两种物质都对健康有威胁,如果混合使用,每一种物质会使另一种物质更有影响。随后几段具体说明了两种物质混合使用产生的危害。这说明,本文主要讲的是酒精和烟草混合使用产生的危害。A说“致命混合物=酒精+烟草”,这可以表达文章的主题。B和D不能表达文章的主题;C太片面。
单选题 The phrase "synergistic effect" in the last paragraph is closest in meaning to ______.
【正确答案】 D
【答案解析】这是一道词义题。文章第二段指出:由于这种相互作用,那些既不停地抽烟又豪饮酒的人患病的风险可能比那些豪饮但从不吸烟或者不停地抽烟但从不喝酒的人更大;最后一段指出:酒精和烟草的协同效应可能给心血管系统和上呼吸道造成很大的伤害。这说明,该短语应该与interaction的意思相近。D“协同作用”,与文章的意思符合。A、B和C都与文章的意思不符合。
单选题 The main function of the liver is to ______.
【正确答案】 C
【答案解析】这是一道细节题。文章第三段指出:在他的烟雾缭绕的肺后面,他的肝脏已经进入高度警戒状态,以拯救他的生命;这三磅重的化工厂能从血液中清除大部分毒素,它把酒精作为外来异物加以抵抗,并将95%的酒精代谢为其他化学品。这说明,C“从血液中清除大部分毒素”,与文章的意思符合。A、B和D都与文章的意思不符合,
单选题 According to the passage, why does a drink bring serious results to a smoker?
【正确答案】 A
【答案解析】这是一道细节题。文章第二段指出:他喝的酒精本身没有致癌性,但是,它可能充当了溶剂,溶解以焦油形式残留下来的烟草毒物,使致癌物顺利通过口腔和咽喉的隔膜。这说明,A“因为酒精可能充当溶剂”,与文章的意思符合。B和D明显不是原因;C与文章的意思不符合。
单选题 The reason why the brain cells of the person who both smokes and drinks heavily are dying is that ______.
【正确答案】 C
【答案解析】这是一道细节题。文章第四段指出:如果嗜烟者因喝酒而导致酒精中毒,那么他很可能会营养不良;这种营养不良与他已有的缺氧问题结合,他的脑细胞就会因此而逐步死亡。这说明,C“供氧不足和营养不良相互作用”,与文章的意思符合。A和B只是部分原因,不全面;文中没有提到D。