hours过去式是什么

该词没有过去式，hours名词词性，意思是小时、钟头，例如：

1.The treatment should be repeated every two to three hours.这种治疗方法应该每隔两到三小时重复一次。

2.It took two hours to bring the fire under control.花了两个小时才控制住火势。

3.Do it now please ─ not in three hours' time.请现在就干，而不是三个小时之后。