问题
选择题
| 下列关于电磁波的说法正确的是（ ） A．光导纤维中传递信息的光不是电磁波 B．固定电话靠电磁波传递信息 C．电磁波的传播需要介质 D．无线电广播信号是靠电磁波传播的 |
答案
答案：D
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| 下列关于电磁波的说法正确的是（ ） A．光导纤维中传递信息的光不是电磁波 B．固定电话靠电磁波传递信息 C．电磁波的传播需要介质 D．无线电广播信号是靠电磁波传播的 |
答案：D
| 阅读短文还原句子。阅读短文，根据上下文意思，将方框中的句子还原到短文中适当位置，使其通 顺完整。其中有一句不选。 | |
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| Mabel Welton, 62, was in her living room when a piece of dark gray metal hit the roof of her home. 1_____. Because her house in Hessle, UK lies under a flight path. However, after examining the piece, the Royal Air Force (RAF) said that the metal was space junk that fell to Earth. 2_____. "We heard this sound and went outside and saw this hole in the roof," she said. "The metal had broken two tiles (瓦片) and made a mess." Welton said that her granddaughter's boyfriend Richard Sutcliffe had to "put on some oven gloves to get it because it was so hot". The Weltons gave the metal to the police. 3_____. Last Thursday, the RAF said they learned that the metal was space rubbish. 4_____. A great number of pieces from more than 5 000 old satellites are now in space. Most pieces have fallen to Earth without doing damage to people or houses. |