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小学五年级自然关于物体振动发声的知识,有一道实验题是:两只同样的玻璃杯,乙杯中的水少,甲杯中的水多,用铅笔分别敲击甲、
An elementary test of the fifth grade primary school about the vibration of objects is that two of the same glasses have less water in the glass and more water in the glass.