oxen的单数是ox；
ox
n.(阉割的)公牛;去势公牛;饲养的牛；
复数 oxen；
例句
We must lead an ox by the halter.
牵牛要牵牛鼻子。
The ox and the rabbit agreed to take part in the event together.
黄牛与兔子约定一起参加竞赛。
The ox has stepped out one path of going to the side in river.
牛踩出了一条到河边去的小路。
This is the year of the ox in Asia.
在亚洲，今年是“牛”年。
