问题
选择题
下列物质中，属于纯净物的是（ ）
A．食盐水
B．澄清的石灰水
C．液态氧
D．新鲜空气
答案
A、食盐水中含有氯化钠和水，属于混合物．错误；
B、澄清的石灰水中含有水和氢氧化钙，属于混合物．错误；
C、液态氧是由一种物质组成的，属于纯净物．正确；
D、空气中含有氮气、氧气等物质，属于混合物．错误．
故选C．
搜题请搜索小程序“爱下问搜题”
下列物质中，属于纯净物的是（ ）
A．食盐水
B．澄清的石灰水
C．液态氧
D．新鲜空气
A、食盐水中含有氯化钠和水，属于混合物．错误；
B、澄清的石灰水中含有水和氢氧化钙，属于混合物．错误；
C、液态氧是由一种物质组成的，属于纯净物．正确；
D、空气中含有氮气、氧气等物质，属于混合物．错误．
故选C．
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| J.K. Rowling is the writer of Harry Potter, which is now one of the best-sellers in the world. She 1 born in Bristol on July 31st, 1965. She has one sister who is two years 2 than her. Both girls loved 3 to their father read bedtime stories. They especially loved stories about magical (魔幻的) world. Rowling wrote her first story 4 the age of six. On a long train trip in 1990, an idea came to her. She wanted to write about a boy who has magic but he himself doesn't know it. In 1992, Rowling began 5 the first Harry Potter book for young 6 . It appeared in June, 1997. The book was a great success. And the film came out in November, 2001. Now Harry Potter series (系列) is 7 with people of all ages and about sixty 8 books were sold in 200 countries. In this series, Harry is an ordinary boy: polite, friendly, brave and clever. So when children read about Harry, they can imagine being like him. That's 9 Harry Potter series has been so popular. J.K. Rowling is very 10 with the success. Now she's really enjoying life. She says she will go on writing children's books. | ||||
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