|
电力机车 |
381BT |
TXT |
|
|
显微镜 |
1000BT |
TXT |
|
|
导体 |
158BT |
TXT |
|
|
导体和绝缘体 |
200BT |
TXT |
|
|
负打电池 |
317BT |
TXT |
|
|
金属物生锈的原因 |
304BT |
TXT |
|
|
绝缘体 |
176BT |
TXT |
|
|
激光的发现和利用 |
549BT |
TXT |
|
|
天文望远镜 |
104BT |
TXT |
|
|
照片的成因 |
1.14KB |
TXT |
|
|
最早的热气球 |
545BT |
TXT |
|
|
爱迪生的灯泡 |
150BT |
TXT |
|
|
电铃的原理 |
196BT |
TXT |
|
|
密码 |
264BT |
TXT |
|
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TXT |
查看 |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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TXT |
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