dilate

在黑暗中，猫的瞳孔会扩大以吸收更多光线。

In the dark, a cat's pupils ___dilate to let in more light.

教授特别喜欢在课堂上详细讲解历史事件的背景。

The professor loves to ___dilate on the background of historical events in class.

这种药物使他的血管扩张，从而降低了血压。

The medication caused his blood vessels to ___dilate, lowering his blood pressure.