265. Recent studies conducted by doctors show that excessive exposure to the sun's rays causes skin cancer .

　　最近医生所做的研究表明：过度暴露在阳光下会致癌。

　　266. Nationwide surveys conducted in 1997 revealed a dramatic rise in the ownership of television sets , refrigerators , air

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　　conditioners and washing machines .

　　1997年所做的全国范围内的调查显示电视机、电冰箱、空调和洗衣机拥有量大幅升高。

　　267. History tells us that mankind has a tendency to repeat past mistakes .

　　历史告诉我们人类有重蹈覆辙的趋势。

　　268. We have amassed ample objective proof to show the urgent need for crisis intervention in suspected child abuse cases . 我们已经积累了充足的客观证据证明急需干涉可疑的虐待儿童的案件。

　　269. Unfortunately , available evidence fails to establish any direct link between smoking and cancer .

　　不幸的是，现有的证据不能证明抽烟和癌症之间有直接的联系。

　　270. Fortunately , mountains of reliable evidence proves the direct link between smoking and cancer beyond any shadow of the doubt .

　　庆幸的是，大量可靠的证据证明抽烟和癌症有直接联系是毫无疑问的。

　　271. Television violence has contributed directly to rising crime , as evidenced by statistics showing a dramatic rise in copycat crimes .

　　数据显示模仿的犯罪行为有大幅度的增加，这证明电视暴力是犯罪增加的一部分直接原因。

　　272. The introduction of adcance agronomic techniques has contributed greatly to the development of agriculture , as indicated by statistics showing increased output in each of the past five years .

　　数据显示在过去的五年中，每一年的产量都有提高，这表明发达的农业技术的引入对农业发展起到了很大的作用。