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物面上任何一点发出的光经过光学系统到达像面成像的公共出口是

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Some researchers assert that in face-to-face communication,about 70%of information is communicated through speaking,and over 30% sis sent by nonverbal means.

斩波电路中,T= ton+toff

列车的蓄电池是串联起来,构成直流1500V的电压。

超过20KHz的机械波称为超声波。

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