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1·In 1952, the US Air Force began Project Blue Book, a study program on UFOs.

1952年，美国空军开始着手实施“蓝皮书计划”，这是一项针对不明飞行物的研究项目。

2·In 1952, the US Air Force began Project Blue Book, a study program on UFOs.

1952年，美国空军开始着手实施施“蓝皮书计划”，这是一项针对不明飞行物的研究项目。

3·This, together with a decline in sighting activity, led to the dismantling of Project Blue Book in 1969.

这份报告随着目击事件的减少，导致了 1969 年 Blue Book 计划的解散。

4·A second committee was set up in 1966 at the request of the Air Force to review the most interesting material gathered by Project Blue Book.

在1966年，由于空军想要复查Blue Book计划中搜集的最有意思的材料而成立了第二支委员会。

5·The US Air Force, however, insisted: Since the termination of Project Blue Book, nothing has occurred that would support a *resumption of UFO investigations.

但美国空军方面却坚持认为：“自“蓝皮书计划”终止后，没有任何事件可以支持重启UFO调查行动。

6·Thee US Air Force, however, insisted: Since the termination of Project Blue Book, nothing has occurred that would support a resumption of UFO investigations.

但美国空军方面却坚持认为：“自“蓝皮书计划”终止后，没有任何事件可以支持重启ufo调查行动。”