考研英语核心词汇速成胜经Unit 29
一、真题文章(1994年text 4)
"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 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 910,000 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 (胰腺) .
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 (基因) , 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. "
二、译文
癌症专家、微生物学家Robert Weinberg说：“我充分相信，本年代末我们就能够了解关于癌细胞如何产生的大量细节。”他警告说：“但是，有些人认为一旦一个人了解了癌症的原因，那么治疗方法很快就能找到了。请想一想Pasteur吧，他发现了多种导致感染的原因，但是直到五、六十年之后人们才找到治疗的方法。”
今年，在91万患癌症的病人当中50%的人至少能存活5年。国家癌症研究所估计到2000年这个数字将上升到75%。对某些皮肤癌患者来说，患者能存活5年的机率高达90%。但是其他一些种类癌症的存活率仍然令人沮丧——如肺癌是13%，而胰腺癌是2%。
在即存的多达120种癌症中找出癌症是如何运作的并不是一件容易的事。20世界70年代初期，研究人员取得了重大进步，那时研究
责任编辑:zhaotingting
