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来源:雅诚德英语网
The researchers were trying to answer the basic question, why do lasers not exist in nature?
研究者想回答为什么激光器不自然存在这个基本问题。
The researchers were trying to answer the basic question, why do lasers not exist in nature?
研究者想回答为什么激光器不自然存在这个基本问题。