普通蜡烛容易熄灭，有人对此做出改进，研究出一种“吹不灭”的蜡烛．吹灭蜡烛后，蜡烛总能灭而复燃．同学们对此进行了探究．

【初步探究】为何这种蜡烛总能灭而复燃？

【查阅资料】①这种蜡烛芯里包裹一层打火石粉末．打火石是由镁、铝、铁中的一种或二种金属掺入少量稀土元素制成的合金，它的着火点为150℃．当蜡烛燃烧时，金属并不燃烧；但当蜡烛吹灭后，未冷却的金属接触到氧气就发生燃烧，从而使蜡烛复燃．

②镁、铝、铁三种金属中，只有铝能和NaOH溶液反应：2Al+2NaOH+2H₂O=2NaAlO₂+3H₂↑

下列事实，用分子、原子的观点解释合理的是（　　）

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中国幅员辽阔，陆地面积约为960万平方公里，“960万”用科学记数法表示为（   ）

Cooking and Learning
In this E-book package, we have four e-books.

Fun with Food This fun e-book is filled with exercises --- photo tests, word exams, riddle games coloring pages and exercises on learning more about food.	Kids Food Science Experiments Learn more about science and cooking with these food science experiments and instructions for kids.
Food Facts E-Book To go with the kids cooking lessons e-book, we’ve put our food facts into one e-book. Each part is easy to print off. You can keep it in the kitchen and teach kids facts about the food we eat. The Food Facts E-Book has over 60 pages.	Kids Cooking Lessons E-Book We’ve brought all our kids cooking lessons together into one easy e-book. We have a unit for each age group. This e-book is just planned to help you with cooking experience in the kitchen. If you’d like our lessons in e-book form with some learning exercises and other things, then this e-book is for you.