1994 Passage 4 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 may have the idea that once one understands the causes, the cure will rapidly follow. Consider 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 910000 people who suffer from cancer will survive at least five years. In the year 2000, the National Cancer Institute estimates, that figure will 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 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 into 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 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 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.63. The example of Pasteur in the passage is used to _.A predict that the secret of cancer will be disclosed 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 conquered64. The author implies that by the year 2000, _.A there will be a drastic rise in the five-year survival 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 wont be a drastic increase of survival rate of all cancer patients65. Oncogenes are cancer-causing genes _.A 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 cell cant turn off66. The word dormant in the third paragraph most probably means _.A deadB ever-presentC inactiveD potential重点词汇：infection /in5fekFEn/ （传染；感染）即in+fect+ion，in-在内，fect词根“做”，-ion名词后缀，“在里面起作用”感染；动词形式为infectin+fect。参effective（有效的），2002年Text 1。Grief, like pleasure, infects the atmosphere. A first glance into any home is enough to tell you whether love or despair reigns there.忧伤与快乐一样，感染着气氛。无论哪一家，只要看上一眼，就足以得知主宰那里的是爱还是绝望。pancreas /5pAnkriEs/ （胰腺）看作pan+cr+eas，pan盘，cr看作crack，eas看作复数形式(es)，“许多盘破裂的胰腺”。oncogene /5CnkE7dVi:n/ （致癌基因）onco+gene，onco词根“肿瘤”，gene基因。dormant /5dC:mEnt/ （静止的；休眠的）即dorm+ant，dorm词根“睡觉”，-ant形容词后缀，“像睡觉那样的”休眠的。同根词：dormitorydorm+itory后缀表“地方”睡觉的地方（集体）宿舍。oncologist /CN5kClEdVist/ （肿瘤学家）onco+logist，onco词根“肿瘤”，-logist后缀“学家”。counteract /7kauntE5rAkt/ （v.抵抗；消除）即counter+act，counter-前缀“反”（如counter-clockwise逆时针方向），act行动，故“反着行动”抵抗。The doctor gave him some medicine to counteract the effect of the poison.医生给他一些药解毒。ever-present 经常存在的。难句解析：But, he cautions, some people may have the idea that once one understands the causes, the cure will rapidly follow. Consider Pasteur, he discovered the causes of many kinds of infections, but it was fifty or sixty years before cures were available.此句是一个直接引语，注意引语中有两个句子，前面的句子有一个复杂的同位语从句that once one understands the causes, the cure will rapidly follow修饰the idea，而后面提到了一个例子，句中有一个but，它后面的it指代前面整句话。注意引语中两个句子之间的关系，后者是用来驳斥前面一句中那些人的错误想法的，作者在这里举的是一个反例。The researchers made great progress in the early 1970s, when they discovered that oncogenes, which are cancer-causing genes, are inactive in normal cells.此句主句是The researchers made great progress in the early 1970s，后面有一个when引导的定语从句修饰the early 1970s，而在这个定语从句中还有一个宾语从句，在宾语从句中又有一个非限定性定语从句which are cancer-causing genes修饰oncogenes。注意此句中有超纲词oncogenes，但是我们可以从后面修饰它的定语从句推出其确切含义，这也是常用到的阅读方法之一，即可以用定语从句来反推所修饰词的意思。The exact mechanisms involved are still mysterious, but the likelihood that many cancers are initiated at th