1、全國(guó)英語(yǔ)專八考試閱讀題型基礎(chǔ)訓(xùn)練“I have great confidence that by the end of the decade well know in vast detail how cancer cells arise,” says microbiologist Robert Weinberg, an expert on cancer. “But,” he cautions, “some people have the idea that once one understands the causes, the cure will rapidly follow. Consid

2、er Pasteur, he discovered the causes of many kinds of infections, but it was fifty or sixty years before cures were available.”This year, 50 percent of the 910,000 people who suffer from cancer will survive at least five years. In the year 2000, the National Cancer Institute estimates, that figure w

3、ill be 75 percent. For some skin cancers, the five-year survival rate is as high as 90 percent. But other survival statistics are still discouraging - 13 percent for lung cancer, and 2 percent for cancer of the pancreas.With as many as 120 varieties in existence, discovering how cancer works is not

4、easy. The researchers made great progress in the early 1970s, when they discovered that oncogenes, which are cancer-causing genes, are inactive in normal cells. Anything from cosmic rays to radiation to diet may activate a dormant oncogene, but how remains unknown. If several oncogenes are driven in

5、to action, the cell, unable to turn them off, becomes cancerous.The exact mechanisms involved are still mysterious, but the likelihood that many cancers are initiated at the level of genes suggests that we will never prevent all cancers. “Changes are a normal part of the evolutionary process,” says

6、oncologist William Hayward. Environmental factors can never be totally eliminated; as Hayward points out, “We cant prepare a medicine against cosmic rays.”The prospects for cure, though still distant, are brighter.“First, we need to understand how the normal cell controls itself. Second, we have to

7、determine whether there are a limited number of genes in cells which are always responsible for at least part of the trouble. If we can understand how cancer works, we can counteract its action.”習(xí)題1.The example of Pasteur in the passage is used to _.A predict that the secret of cancer will be disclo

8、sed in a decadeB indicate that the prospects for curing cancer are brightC prove that cancer will be cured in fifty to sixty yearsD warn that there is still a long way to go before cancer can be conquered2. The author implies that by the year 2000, _.A there will be a drastic rise in the five-year s

9、urvival rate of skin-cancer patientsB 90 percent of the skin-cancer patients today will still be livingC the survival statistics will be fairly even among patients with various cancersD there won t be a drastic increase of survival rate of all cancer patients3. Oncogenes are cancer-causing genes _.A

10、 that are always in operation in a healthy personB which remain unharmful so long as they are not activatedC that can be driven out of normal cellsD which normal cells cant turn off4. The word “dormant” in the third paragraph most probably means _.A deadB ever-presentC inactiveD potential全文翻譯“我有極大的信

11、心相信到這個(gè)十年期結(jié)束時(shí)我們將會(huì)詳盡地知曉癌細(xì)胞的生成原因，”一位癌癥專家和微生物學(xué)家羅伯特溫伯格說(shuō)道。“但是，”他告誡說(shuō)，“有些人認(rèn)為一旦人們弄清了病因，治療方法很快就會(huì)跟上。例如法國(guó)細(xì)菌學(xué)家巴斯德，他發(fā)現(xiàn)了許多傳染病的成因，但治療方法卻在五六十年后才問(wèn)世。”今年，91萬(wàn)癌癥患者中有一半將至少再活5年。國(guó)家癌癥研究所估計(jì)，到2000年存活率將升至75%。現(xiàn)在對(duì)于一些皮膚癌來(lái)說(shuō)，5年期的存活率高達(dá)90%，但其他類型癌癥的存活數(shù)據(jù)卻仍令人沮喪肺癌13%，胰腺癌2%。癌癥種類現(xiàn)有多達(dá)120多種，發(fā)現(xiàn)其規(guī)律實(shí)屬不易。研究者在70年代取得了很大的進(jìn)展。當(dāng)時(shí)他們發(fā)現(xiàn)致癌基因，即那些可以引起癌癥的基因，在

12、正常細(xì)胞中是不活動(dòng)的。從宇宙射線到輻射到日常飲食，任何東西都有可能激活處于沉寂狀態(tài)中的致癌基因，但是如何激活不為人所知。如果若干致癌基因被激活，而細(xì)胞無(wú)力排除，它們就演變成了癌細(xì)胞。導(dǎo)致癌變的確切機(jī)制仍然是個(gè)謎，但是許多癌癥始于基因這一可能性表明我們將永遠(yuǎn)不能預(yù)防所有癌癥。“變化是進(jìn)化過(guò)程中的一個(gè)正常部分，”腫瘤專家威廉海沃德說(shuō)道。環(huán)境因素永遠(yuǎn)無(wú)法完全消除，正如海沃德所指出的那樣：“我們無(wú)法準(zhǔn)備出一種抗宇宙射線的藥?！敝伟┣熬半m然遙遠(yuǎn)，但卻越來(lái)越明朗了。“首先，我們需要了解正常細(xì)胞如何控制其本身。其次，我們必須查明細(xì)胞中是否有一定數(shù)量的基因總是造成至少部分麻煩的原因。如果我們能弄清癌癥的原理，

13、我們就能采取相應(yīng)的措施?！敝攸c(diǎn)句The prospects for cure, though still distant, are brighter.該句意義：該句雖然簡(jiǎn)短，但是其將轉(zhuǎn)折語(yǔ)氣以插入語(yǔ)的結(jié)構(gòu)進(jìn)行了表達(dá)。在考研寫(xiě)作中，我們可以完全參照寫(xiě)出相應(yīng)的句子。比如：The prospect for eliminating pollution, though still distant, is brighter. 消除污染的前景盡管遙遠(yuǎn)，但是已經(jīng)更加明朗了。習(xí)題答案答案DDBC1.The example of Pasteur in the passage is used to_.1.文章以Pa

14、steur為例的目的是_。A predict that the secret of cancer will be disclosed in a decadeA 預(yù)言十年內(nèi)癌癥的秘密將會(huì)被徹底揭開(kāi)B indicate that the prospects for curing cancer are brightB 說(shuō)明癌癥治愈前景值得樂(lè)觀C prove that cancer will be cured in fifty to sixty yearsC 證明五六十年后癌癥將被治愈D warn that there is still a long way to go before cancer c

15、an be conqueredD 提醒人們徹底戰(zhàn)勝癌癥的道路還很長(zhǎng)2.The author implies that by the year 2000, _.2.作者暗示，到2000年_。A there will be a drastic rise in the five-year survival rate of skin-cancer patientsA 皮膚癌患者的五年存活率會(huì)急劇增長(zhǎng)B 90 percent of the skin-cancer patients today will still be livingB 如今90%的.皮膚癌患者仍然健在C the survival sta

16、tistics will be fairly even among patients with various cancersC 各種癌癥患者的存活幾率基本一致D there won t be a drastic increase of survival rate of all cancer patientsD 不是所有癌癥患者的存活率都將急劇上升3.Oncogenes are cancer-causing genes_.3.致癌基因_。A that are always in operation in a healthy personA 總活動(dòng)在健康人體中B which remain unharmful so long as they are not activatedB 只要不被激活，就保持無(wú)害C that can b