题干

向一定溶质质量分数的过氧化氢溶液中加入少量二氧化锰,立即有大量的氧气产生。下列说法正确的是(  )

A:过氧化氢中含有水和氧气

B:过氧化氢能使二氧化锰分解放出氧气

C:二氧化锰能加快过氧化氢分解生成水和氧气

D:该反应中有过氧化氢和二氧化锰两种反应物,不属于分解反应

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C

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    Every people uses its own special word to show its ideas and feelings. Some of these expressions(表达,说法) are commonly used for many years. Others are popular for just a short time. One such American expression is “Where's the beef?” It is used when something is not as good as it is said to be. In the early 1980s “Where's the beef?” was one of the most popular expressions in the United States. It seemed as if everyone using it at the time.

    Beef, of course, is the meat from a cow, and food is more popular in America than a hamburger made from beef. In the 1960s a businessman named Ray began building small restaurants that sold hamburgers at a low price. Ray called this “McDonald's”. Ray became one of the richest businessmen at last in America.

    Other business people watched his success. Some of them opened their own hamburger restaurants. One company called “Wendy's” said its hamburgers were bigger than those sold by McDonald's or anyone else. The Wendy's Company began to use the expression “Where's the beef?” to make people know that Wendy's hamburgers were the biggest. The Wendy's television advertisement showed three old women eating hamburgers. The bread that covered the meat was very big, but inside there was only a bit of meat. One of the women said she would not eat a hamburger with such a little piece of beef. “Where's the beef?” she shouted in a funny way. The advertisement for Wendy's hamburger restaurants was success. As we said, it seemed everyone began using the expression “Where's the beef?”.