单词：germanium-doped silica
单词：germanium-doped silica 相关文章
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英语听力文摘 English Digest
Knock, knock. Mr Matthews? What a surprise! Where're your parents? They didn't bring me. I took the bus. Actually they don't even know I'm here. I've brought you a germanium. Geranium. Didn't I say germanium? Yes, you did. In fact, germanium is a che
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