The Pony Express ponies were mustangs. These were small, wild horses. The horses were less than five feet tall. They galloped almost twelve miles an hour.

驿马快公司的马匹都是体形小的野马，它们身高不过五英尺，奔跑时时速可达12英里。

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They were ten or twelve feet tall, each four hundred pounds or more.

NEWYORKER: Max at Sea

It has twelve-foot-tall tires, and its cab sits twenty-one feet off the ground.

NEWYORKER: Unconventional Crude