The spatial objects oriented in underground coalmine mining have the features of gray and dynamic change.

地下煤矿开采所面对的空间目标具有灰色、动态变化的特征。

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The spatial objects oriented in underground coalmine mining have the features of gray and dynamic change.

地下煤矿开采所面对的空间目标具有灰色、动态变化的特征。

youdao