Near the plowed fields curved and faded, and the few hogs nosing in the furrows looked like large spotted stones.

颜色褪尽的耕地，一群鼻子拱出皱纹的猪就像大大的,带着斑点的石头。

耶鲁公开课 - 1945年后的美国小说课程节选

Irving Fisher also drew on the curve a production possibility frontier for society, which he made downward-curved.

欧文·费雪还画了一条曲线,代表了社会的生产可能性边界PPF,这是一条向下的曲线

耶鲁公开课 - 金融市场课程节选