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在物理学中，把传播声音的物质叫做______，它可以是气体，还可以是______或______．我们平时听到的声音主要是通过______传播的．

答案

在物理学中，把传播声音的物质叫做介质，它可以是气体，还可以是液体或固体；我们平时听到的声音只要是通过空气传播的．

故答案为：介质，液体，固体，空气．

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施工全煤厚孔顶、底时，若因巷道高度不够（）米以上，必须用坡度规量出施工角度，每一巷的煤厚施工方位应一致。
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单项选择题

"I would almost rather see you dead." Robert S. Cassatt, a leading banker of Philadelphia, shouted when his twenty-year-old eldest daughter announced that she wanted to become an artist.
In the 19th century, playing at drawing or painting on dishes was all right for a young lady, but serious work in art was not. And when the young lady’s family ranked among the best of Philadelphia’s social families, such an idea could not even be considered.
That was how Mary Cassatt, born in 1844, began her straggle as an artist. She did not tremble before her father’s anger. Instead; she opposed him with courage and at last made him change his mind. Mary Cassatt gave up her social position and all thought of a husband and a family, which in those times was unthinkable for a young lady. In the end, after long years of hard work and perseverance, she became America’s most important woman artist and the internationally recognized leading woman painter of the time.

How did Mr. Cassatt react when his daughter made her announcement
[A] He feared for her life.
[B] He was very angry.
[C] He nearly killed her.
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