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声音的产生与传播

> 百米赛跑的终点计时员，必须在看到发令枪冒烟就开始计时，不能听到枪声才计时，这是因为（　　） A．看枪冒烟时，计时比较方便 B．怕离起点较远，声音嘈杂听不清枪声 C．听到枪声计时不够准确，使成绩偏高 D．听到枪声计时不够准确，使成绩偏低

问题：

发布时间：2024-09-10

百米赛跑的终点计时员，必须在看到发令枪冒烟就开始计时，不能听到枪声才计时，这是因为（　　）

A．看枪冒烟时，计时比较方便

B．怕离起点较远，声音嘈杂听不清枪声

C．听到枪声计时不够准确，使成绩偏高

D．听到枪声计时不够准确，使成绩偏低

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