travel的过去式和过去分词

　　双语例句：

　　Sound travels better in water than in air.

　　声音在水中比在空气中传播得快。

　　I've always had a yen to travel around the world.

　　我一直非常渴望周游世界。

　　I go to bed early if I'm travelling the next day.

　　如果第二天去旅行我就早睡。

　　Flying is quite the best way to travel.

　　航空绝对是最佳旅行方式。

　　When I finished college I went travelling for six months.

　　我大学毕业后在外旅行了六个月。

　　We lost our money when the travel company went bust.

　　旅行社破产，我们的钱都赔了进去。