zài / pāo / wù / xiàn / de / dìng / yì / zhōng / zhǔn / xiàn / hé / jiāo / diǎn / tóng / yàng / zhòng / yào

在抛物线的定义中，准线和焦点同样重要。

In the definition of a parabola, the directrix is just as important as the focus.