For four decades, Mr. Knight, who is now 69 years old, built the Beaverton, Ore., company into the industry titan while maintaining a personal reputation for seclusion and secrecy.

现年69岁的奈特在过去40多年中把这家位于俄勒冈州比弗顿的公司打造成了行业巨头，而他本人则以低调和隐秘闻名。

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During many decades study, scientists have produced different types of bio-fuels that into four types: first generation, second generation, third generation and fourth generation.

通过几十年的研究，科学家们生产出的不同生物燃料分为四类：第一代，第二代，第三代和第四代。

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Greenberg is the man who spent nearly four decades building AIG into a global insurance power.

WSJ: Ex-CEO Greenberg: Don't blame me for AIG failure

It took years of focused effort among many nations to bring the NPT into force four decades ago and to sustain it as the most widely embraced nuclear agreement in history.

WHITEHOUSE: The White House

During the four decades from the 1960s, women have been marching into America's labour force in ever greater numbers.

ECONOMIST: Are 5.1m Americans missing from the unemployment figures?