Horses were domesticated 6,000 years ago on the grasslands of Ukraine, southwest Russia and west Kazakhstan, according to a study by a Cambridge University team.
To horse around 意思是鬧著玩兒，嬉戲玩耍。
During the school holidays there was no peace in the house. Johnny and Annie horsed around all day, every day.
I was horsing around with some friends in the library - we got told to leave.
短語 from the horse's mouth 意思是指消息來自最直接、最可靠的出處。
Interest rates are definitely going up next month. The finance minister was talking about it on TV - I heard it from the horse's mouth.