比如，同时对两个CSS属性做动画，但又得为它们定义不同的缓动函数。

For example, you may want to animate two CSS properties but use a different easing function for each one.

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这里是两个自定义时间线的动态演示。“进场”和“离场”都持续200毫秒，但它们有不同的缓动函数。“离场”动画会在轻微的延迟之后开始。

Here are a couple of custom timings in action. Both enter and leave last for 200 milliseconds but they have different easings. The leave begins after a slight delay.

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