下列有关三江平原的叙述，正确的是

中国政府为实现更多人“住有所居”的梦想做出了不懈的努力。2009年政府投入了4000亿元实施保障性安居工程。这将有利于
①通过行政手段，遏制部分城市房价过快上涨的势头 
②调节资源配置，满足普通百姓对住房的需求 
③缓解住房供需矛盾，稳定房价       
④从根本上解决“住房难”问题，促进房地产市场健康发展

假设你叫林洋，收到了你的笔友Susan的一封信，请你给她写一封回信。在信中回答她的问题，提出你的建议，并就此事谈谈你的看法。
Dear Lin Yang,
I have a problem these days. My mother doesn’t allow me to watch TV even on weekends. She says as a middle school student, my job is to study. After I finish my homework, she says, I should read books and watching TV is bad for me. But I think I need a rest and watching TV helps me learn a lot too.
Do you have the same problem? What do you think of my mother’s decision? What should I do?
Yours,
Susan

下列物质中属于纯净物的是（ ）

我国最大的煤炭生产基地是（　　）