The demand curve is a graph of this relationship with the price on the vertical axis and the quantity demanded on the horizontal axis.

把价格与需求量联系在一起的向右下方倾斜的曲线被称为需求曲线。

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For example, a graph of the relationship Between real Numbers and their squares matches each real number on a horizontal axis with its square on a vertical axis.

举例来说，实数与其平方的关系图表符合了横坐标上每个实数皆对应到纵坐标上的平方值。

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On the horizontal axis of each graph, we have total traffic-related air pollution exposure, increasing in parts per billion (a part here would be a drop in a billion drops) from left to right.

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