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【单选题】
德瑞克公式的推算，我们银河系里面可以沟通的文明数基本取决于（ ）数。
A.
智慧文明能够存在的时间年限
B.
存在类似地球的行星
C.
存在类似太阳的恒星
D.
存在科技文明的生物群体?
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参考解析：
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【单选题】Isn’t it surprising that scientists have a better understanding of how many stars there are in the galaxy (银河系) than how many species there are on Earth Their estimates of global species diversity var...
A.
The soil and the deep sea belong to communities that haven’t been fully explored.
B.
It is surprising news wherever new species are discovered in the deep sea.
C.
About 90 million species are believed to live in the deep sea.
D.
A million species in the deep sea have been discovered and named.
【单选题】根据文意，天体物理学家发现的银河系“甘戈特里波”是一种（）。
A.
冰川一样的结构
B.
像“羽毛”一样的气体卷须
C.
连接银河系两条旋臂的固体星系结构
D.
冷一氧化碳气体云