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考研英语阅读理解真题及详解No.67

[日期:06-05] 来源:网络  作者:未知 [字体: ]

考研英语阅读理解真题及详解No.67




  "I have great confidence that by the end of the decade we'll 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 can't 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 decade
  [B] indicate that the prospects for curing cancer are bright
  [C] prove that cancer will be cured in fifty to sixty years
  [D] warn that there is still a long way to go before cancer can be conquered

64. The author implies that by the year 2000, ________.
  [A] there will be a drastic rise in the five-year survival rate of skin-cancer patients
  [B] 90 percent of the skin-cancer patients today will still be living
  [C] the survival statistics will be fairly even among patients with various cancers
  [D] there won't be a drastic increase of survival rate of all cancer patients

65. Oncogenes are cancer-causing genes ________.
  [A] that are always in operation in a healthy person
  [B] which remain unharmful so long as they are not activated
  [C] that can be driven out of normal cells
  [D] which normal cell can't turn off

66. The word "dormant' in the third paragraph most probably means ________.
  [A] dead
  [B] ever-present
  [C] inactive
  [D] 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infect←in+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:dormitory→dorm+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

①"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。

②The 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。

③The 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.
▲此句是用but连接的复合句,注意前面的involved表示“相关的”,而后面的半句的主干是the likelihood suggests that...,里面又包含有一个同位语从句和宾语从句。
△注意看清句子结构,而后面的likelihood表示“可能性”。

④Environmental factors can never be totally eliminated; as Hayward points out, "We can't prepare a medicine against cosmic rays."
▲此句用分号隔开,前面是一个简单的被动语态,而后面是一个直接引语。
△如果我们了解分号的用法,就知道它经常用来连接两个意思相仿或相对的句子。而在这里,分号后面的部分就是进一步说明前面的意思,那么我们也就知道cosmic rays是environmental factors的一个个例。

试题解析

63. [D] 该项意为:提醒人们彻底战胜癌症的道路还很长。
  本文第1段中所举的巴斯特的例子在于否定本段第2句提到的某些人的观点:一旦找到病因,治疗方法会立刻找到(rapidly follow),而在于说明第4句中所阐明的道理。
  [A]原文第1段第1句引用了Weinberg的话,他认为人们在近十年内会对癌症的病因有很大的了解,但这并不意味着会彻底揭开(disclose)癌症的秘密。另外,这也不是举巴斯特的例子所要说明的问题。
  [B]意为:指出治愈癌症的前景是非常乐观的。本文作者相信这一点,但这并不是举巴斯特这个例子所要说明的观点。
  [C]在巴斯特找到传染病病因五六十年之后,才找到治疗方法,但这并不意味着五六十年以后也肯定会找到治愈癌症的方法。

64. [D] 意为:各种癌症患者的平均存活率不会有大幅度的增加。
  文章第二段用数据说明了能够继续生活五年以上的病人的数量的比例,这一比例增加是可喜的,但能完全从病魔中生存下来的人仍然不会有大幅度的增加。
  [A]文章只提到了目前可以存活五年的皮肤癌病人的比例是90%(注意文章原句用的是一般现在时),但未提到2000年将会怎样。
  [B]由对[A]项的分析可以看出,考生无法了解2000年有多大比例的癌症病人还健在。
  [C]本题中“fairly even”意为“基本不变”。对这项所表达的内容也无法证实。在解释[D]项时,我们曾指出各种癌症患者的平均存活率不会有大幅度的增加,但这并不意味着根本没有增加。

65. [B] “activate”在此意为“激活,使活动起来”。
  文章第3段第4句指出:如果几个致癌基因(oncogene)被激活,细胞又无法抵御它们的侵害的话,细胞就会发生癌变。
  [A]参阅文章第3段第2句。该项表达的内容与事实相反。
  [C]文章第3段指出,致癌基因存在于健康细胞(normal cells)中。
  [D]原文第3段第4句“unable to turn them off”只表达了一个假设,相比之下,[D]表达的是一个事实。

66. [C] “dormant”意为“潜伏的”,与第3段第2句中“inactive”一词是同义。
  [A]“dead”的意思不对。
  [B]“ever-present”意为“无时无处不在”也不对。
  [D]“potential”意为“潜在的”,与同一句中“activate”(make... active)的意思不搭配。

全文翻译

  “我有极大的信心相信到这个十年期结束时我们将会详尽地知晓癌细胞的生成原因,”微生物学家罗伯特·温伯格,一位癌症专家如此说道,“但是,”他又告诫说,“有些人认为一旦人们弄清了病因,治疗方法很快就会跟上。其实不然,想想法国细菌学家巴斯德,他发现了许多传染病的成因,但治疗方法却在五六十年后才问世。”
  今年,91万癌症患者中有一半将至少再活5年。国家癌症研究所估计,到2000年存活率将升至75%。现在对于一些皮肤癌来说,5年期存活率高达90%,但其他类型癌症的存活数据却仍令人沮丧——肺癌13%,胰腺癌2%。
  癌症现有种类多达120多种,发现其规律实属不易。研究人员在70年代早期取得了很大进展,他们发现导致癌症的癌基因在正常细胞里是不活跃的。从宇宙射线、辐射到日常饮食,任何东西都可能激活一个处于静止状态下的致癌基因,但如何激活尚不为人知。如果若干癌基因被激活,细胞无力排除也就演变成了癌细胞。
  导致癌变的确切机制仍是个谜,但许多癌症始于基因这一可能性表明我们将永远不能预防所有癌症。“变化是进化过程中的一个正常部分,”肿瘤专家威廉·海沃德说道。环境因素永远无法完全消除,正如海沃德所指出的那样:“我们无法准备出一种抗宇宙射线的药。”
  治癌前景尽管遥远,但已越来越明朗。
  “首先,我们需要了解正常细胞如何控制自己。其次,我们必须查明细胞中是否有一定数量的基因对至少部分麻烦总是负有责任。如果我们能弄清癌症的活动规律,我们就能采取相应的措施。

 

 

 

 

 

 

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