人口统计学家约尔·柯特金指出,加州在干旱年份总是有火灾,这至少始于西班牙人统治时期。
Joel Kotkin, a demographer, points out that California has always had fires during dry years, at least since the time of the Spaniards.
科学家估计柯伊伯带很有可能存在有几万个大小超过60英里(100公里)的冰矮天体,还有数量在万亿以上的彗星。
Scientists estimate the Kuiper belt is likely home to hundreds of thousands of icy bodies larger than 60 miles (100 km) wide, as well as an estimated trillion or more comets.
巴塞罗纳环境流行病研究中心的流行病学家马诺里斯•柯格维纳斯表示,这项研究还处于初期,建议人们停止游泳为时尚早。
The work is too preliminary to suggest that people should stop swimming, said Manolis Kogevinas, an epidemiologist at the Center for Research in Environmental Epidemiology in Barcelona.
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