2022年3月24日
carbon
摘要： Carbon (from Latin: carbo "coal") is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons 阅读全文
posted @ 2022-03-24 22:39 华容道专家 阅读(871) 评论(0) 推荐(0)