他们还通过观察卫星图所显示的非法伐木比率对滥发森林所造成的威胁进行了研究。

They also studied the threat of deforestation by looking at satellite imagery showing the rate of illegal logging.

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可是，出于好奇，研究者保持这三个比率完全相同，他们开始反复观察同一种波形一次又一次的形成，甚至在尺寸迥异的圆筒中。

Curiously, however, if the researchers kept all three ratios identical, they began to spot the same waves forming again and again, even in cylinders of very different sizes.

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但据研究人员在环境健康观察期刊在线版上发表的报告显示，从1970年开始，美国和日本的男女出生比率开始下降。

But since 1970, the U. s. and Japan have experienced a downward shift in this male-to-female birth ratio, researchers report in the online edition of the journal Environmental Health Perspectives.

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