问题
选择题
| 关于电磁场和电磁波，下列叙述中正确的是（ ） |
| A．变化的电场能够产生磁场，变化的磁场也能产生电场 B．电磁波和机械波都只能在介质中传播 C．有的电磁波是横波，有的电磁波是纵波 D．电磁波穿过介质的分界面时频率会发生变化 |
答案
答案：A
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| 关于电磁场和电磁波，下列叙述中正确的是（ ） |
| A．变化的电场能够产生磁场，变化的磁场也能产生电场 B．电磁波和机械波都只能在介质中传播 C．有的电磁波是横波，有的电磁波是纵波 D．电磁波穿过介质的分界面时频率会发生变化 |
答案：A
| 根据短文内容，从方框内选择合适的单词并用其适当形式填空，使短文完整、连贯。 | |
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| At a concert, a girl’s looking up with tears and (1)________ her arms up in the air. You may (2)______ what is wrong with her. I can tell you the reason: She is (3)________ moved by the music. Music can move you by the lyrics, the beat or the rhythm (节奏). Lyrics are sometimes the (4)______ part of a song. But my favorite parts of a song are the beat and the rhythm. (5) _________, I love the good guitar melody (旋律). Would you like to know why songs (6)________ you feel so great inside? Well, I would personally say that lyrics are a key (7)________. You probably (8)________ with the ideas of the lyrics in your favorite songs. You feel great just because your (9)________ ideas and thoughts are in the songs! So, the next time you (10)_________ to a song, see whether the song touches (触动) you by the lyrics. |