老师用简单的例子澄清了这个复杂的数学概念。

The teacher used simple examples to ___clarify the complex math concept.

请用这张滤纸过滤水中杂质，使水变澄清。

Please use this filter paper to ___clarify the water by removing impurities.

老师举了一个例子来澄清这个复杂的概念。

The teacher gave an example to ___clarify this complex concept.