dilate的过去式怎么变化

例句：

Red wine can help to dilate blood vessels.

红葡萄酒有助于扩张血管。

At night, the pupils dilate to allow in more light

到了晚上，瞳孔就会扩大以接收更多光线。

The balloon will dilate with air.

气球充气将会膨胀。