watch的过去式是什么为什么

He watched the house for signs of activity.

他注视着那所房子里的动静。

I watched the car until it was out of sight.

我目送汽车，直到看不见为止。

We watched the balloon riding high above the fields.

我们看着气球高高地飘浮在田野上空。

We watched the lions from the safety of the car.

我们从车里看狮子，很安全。

I watched the programme from beginning to end.

这个节目我从头看到了尾。