题目

请用相关的化学知识回答下列生活中的问题（1）合理膳食，均衡营养对青少年的身体发育具有重要意义．①牛肉、鸡蛋等食物中富含的营养素是；②酱油中添加铁元素有助于防止因缺铁引起的 ． （2）很多人喜欢穿纯棉服装，因为与合成纤维相比棉纤维具有的优点．（3）食品包装中充氮气以防腐，其原因是氮气 ． （4）雾霾是当前中国最受关注的环境问题之一①雾霾形成的原因之一是大量使用了某些化石燃料，如（填一种）；②为了减少雾霾，确保请将这些句子按正确的顺序排列A. That's OK. Thank you. We can be good friends.B. Hello! Are you from the USA?C.I speak English. I also speak Chinese. Let's help each other. Is that OK'?D. Can you speak Chinese?E. Yes, but a little. What language do you speak?F. No ,I'm from Australia. What about you?G. Hello!H．I'm from France.I. I want to learn Chinese history.J. Why do you come to China?1._________ 2. _________ 3. _________4. _________5. _________ 6. _________7. _________8. _________9. _________10. _________