问题
选择题
生活中的下列物质，属于纯净物的是（ ）
A．大理石
B．酒精
C．生石灰
D．“雪碧”可乐
答案
A、大理石主要成分是碳酸钙，还含有其他杂质，属于混合物，故A错；
B、我们生活中的酒精是酒精和水的混合物，属于混合物，故B错；
C、生石灰是由氧化钙一种物质组成，属于纯净物，故C正确；
D、“雪碧”可乐含有水、碳酸等物质，属于混合物，故D错．
故选C．
搜题请搜索小程序“爱下问搜题”
生活中的下列物质，属于纯净物的是（ ）
A．大理石
B．酒精
C．生石灰
D．“雪碧”可乐
A、大理石主要成分是碳酸钙，还含有其他杂质，属于混合物，故A错；
B、我们生活中的酒精是酒精和水的混合物，属于混合物，故B错；
C、生石灰是由氧化钙一种物质组成，属于纯净物，故C正确；
D、“雪碧”可乐含有水、碳酸等物质，属于混合物，故D错．
故选C．
People often call the plastic bags “white pollution”. 小题1:, it becomes the worst invention for the human. It is reported that it takes 100–200 years to break down the plastic bags completely. However, a 16-year-old high-school Canadian student called Daniel Byrd discovered the way to break down the plastic bags! The idea of the invention comes from his housework. 小题2: . Every time, when he opens the closet, the plastic bags fly out. This makes him very angry. 小题3: . With his teacher’s help, he found that when he put the two germs（细菌） mixture up and that made the plastic bags break down quickly. He made an experiment first. He put some earth germs and plastic bags together. After 12 weeks, he found the plastic bags had been broken down. 小题4: . The experiment also showed that the plastic bags could be broken down in three months. And they only gave out some water and little carbon dioxide (CO2). Now Byrd has got 30 thousand dollars from his invention. 小题5:. He has also got a lot of award from many universities.
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