他们在不规则的时间间隔见面。

They met at ___irregular intervals.

更糟的是，用餐时间不规律，结果我很瘦。

To make matters worse, the meal times are ___irregular, so as a result I am skinny.

公交车服务不规律，所以我经常得等。

The bus service is ___irregular, so I often have to wait.