Tink agreed to travel by hat if it was carried in the hand.

婷咔同意坐在帽子里旅行，条件是帽子必须用手提着。

I always travel by underground.

我总是乘地铁。

It'll work out cheaper to travel by bus.

算来还是乘公共汽车便宜些。

They could travel by horse and car.

他们可以骑马和开车去旅行。

They travel by ship.

他们乘船旅行。