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问题 选择题

下列说法中正确的是

A．加热高锰酸钾完全反应后的剩余物是纯净物

B．铁丝在空气中剧烈燃烧，火星四射，说明氧气具有可燃性

C．1L芝麻与1L大米混合，总体积小于2L。可用微粒之间有间隙的性质来解释

D．实验室制取二氧化碳的反应中，所有元素的化合价都没有变化

答案

答案：D

题目分析：高锰酸钾完全反应后的剩余物是锰酸钾和二氧化锰，属混合物，A错误；铁丝在空气中不能燃烧，在氧气中剧烈燃烧，火星四射，说明氧气具有助燃性，B错误；芝麻与大米都属于混合物，不能用分子的观点解释，C错误；实验室制取二氧化碳的反应是复分解反应，复分解反应中元素的化合价不变，D正确。故选D。

填空题

35.60元读作（   ），就是（    ）元（    ）角（    ）分；0.73元读作（    ），就是（    ）元（    ）角（   ）分。
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单项选择题

(一)


The Man of Many Secrets—Harry Houdini—was one of the greatest American entertainers in the theater next century. He was a man famous for his escapes—from prison cells, from wooden boxes floating in rivers, from locked tanks full of water. He appeared in theaters all over Europe and America. Crowds came to see the great Houdini and his "magic" tricks.
Of course, his secret was not magic, or supernatural powers. It was simply strength. He had the ability to move his toes as well as he moved his fingers. He could move his body into almost any position he wanted.
Houdini started working in the entertainment world when he was 17, in 1891. He and his brother Theo performed card tricks in club in New York. They called themselves the Houdini Brothers. When Harry married in 1894, he and his wife Bess worked together as magician and assistant. But for a long time they were not very successful. Then Harry performed his first prison escape, in Chicago in 1898. Harry persuaded a detective to let him try to escape from the prison, and he invited the local newspapermen to watch.
It was the publicity that came from this that started Harry Houdini’s success. Harry had fingers trained to escape from handcuffs and toes trained to escape ankle chins. But his biggest secret was how he unlocked the prison doors. Every time he went into the prison cell, Bess gave him a kiss for good luck—and a small skeleton key, which is a key that fits many locks, pass quickly from her mouth to his.
Harry used these prison escapes to build his fame. He arranged to escape from the local prison of every town he visited. In the afternoon, the people of the town would read about it in their local newspapers, and in the evening every seat in the local theater would be full. What was the result World-wild fame, and a name remembered today.

In the fourth paragraph, the underlined word "this" refers to ______.

A．his first prison escape

B．the year 1898

C．the publicity

D．Harry Houdini’s success
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