第三十五条 从事国际航行船舶的中国籍船员，应当依法持有中华人民共和国海事管理机构颁发的海员证和有关证书。
Thirty years ago, atmospheric scientists began to notice a worrisome trend. They knew that turbulence from storms increases in summer, when hotter and more humid air rises to form thunderheads. And they knew that clear-air turbulence increases in winter, when the temperature drops dramatically at the poles but not in the tropics. That temperature difference drives the jet stream, which creates turbulent eddies and wind shear as it rushes through slower bodies of air. But, on top of these seasonal swings, there seemed to be an over-all trend as well: Earth’s atmosphere was getting rougher.
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