题干

推理是化学学习中常用的思维方法,下列推理正确的是(   )

A:混合物中至少含有两种物质,则混合物中至少含有两种元素

B:硝酸铵溶于水吸收大量的热,则氢氧化钠溶于水吸收大量的热

C:物质在发生化学变化时,原子的种类不变,则元素种类也不会改变

D:利用红磷燃烧的方法可以测定空气中氧气的含量,则利用木炭也可以

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C

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    I believe that my country,Poland,is a perfect example for a place where food is particularly important. When we were little children, we began to understand how much a loaf of bread meant to our parents—to some it might sound silly but for me the custom of kissing bread before you started cutting it was simply amazing. It's not so common nowadays to treat food that way,since you hardly ever bake your own bread. Besides, everyone would call you crazy if you tried to kiss every bread roll before you ate them! But though we no longer make our food from scratch (起点), some customs have been kept—that's why I feel so sorry every time I have to throw any food away—even though I no longer live with my parents and nobody would blame me for this anymore!

    Many people of our nation are still working as farmers, eating what they grow and harvest and therefore enjoying everything more. It's widely known that you value more anything that needs your effort in the first place. In most homes in Poland, especially those of farmers, the whole family would try and have their meals together—extremely difficult now, but so rewarding! You can share other members' troubles and successes, give your children some attention, or just sit down for a moment, instead of rushing through life aimlessly. Furthermore, your body,and stomach in particular will be very grateful for such a time!

    In Poland, a wedding,Christmas or even a birthday is celebrated with a great meal. Women in the house get together and cook ,sometimes for a few days before the event,and the extremely good or unusual food will be remembered and widely talked about.

    You cannot over-value the importance of food in the country. What's more, almost everyone in Poland will be as interested in the topic as I am.