While dot punching, blue annular marks are printed at the positions of the survey dots by a coloring head under the action of a spring.

冲点的同时涂色头依靠弹簧的作用在测量点处印上蓝色圆环标记。

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The percentage of summer, spring, autumn, or winter heavy rain days to annular heavy rain days is 60, 29, 10, or 1, respectively.

夏季、春季、秋季及冬季区域暴雨日 数占总日数的百分比依次为60%、29%、10%及1%。

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