A﹣G是初中化学中常见的物质，其相互反应及转化关系如图所示，部分反应条件省略．已知A是易与人体血红蛋白结合的有毒气体，B是+3价铁的氧化物，A和B反应能生成单质D和一种参与植物光合作用的气体，C是相对分子质量最小的氧化物，F是最轻的气体．

生活中有很多地方涉及物理知识，下列说法正确的是（　　）

完形填空。
    Hello. I'm Jenny. I have a best friend.   1 name is Amy. We are in the same school. We both can sing and dance well. She is as  2 as me.
    At school, my teachers all can make 3   happy. But we must4  white blouse with the long sleeves. I am good 5   maths and English. She 6  English. She thinks it's difficult. Yesterday we7   a party at school. We enjoyed ourselves.
    At spare time, my favourite8   is winter. I like 9  snowmen in winter. But she likes eating ice creams in summer. What a pity!
    In two months' time, we are going to go to middle school. We are very busy every day. We  10   harder than now.

What's Mike going to do this weekend? ____

我国人口的突出特点是（　　）