onprep.在 ... 之上；由 ... 支撑着；在（某一天）；关于；基于adv.穿着；向前（移动)；表示持续性adj.表示已连接、处于工作状态或使用中；发生；值班Onikki奥尼基

1. There were two soldiers on horseback.
   有两个士兵骑着马。
2. Two cowboys rode herd on the cattle being driven to market.
   两个牛仔骑着马，看管着赶往市场上去的牛群。
3. Knights used to tilt on horseback.
   骑士们常骑在马背上用枪刺杀。
4. Fasten the saddle on the horse's back.
   把鞍子系在马背上。
5. Knights used to tilt on horseback.
   骑士们常骑在马背上用枪刺杀。
6. He lifted up his little son, and mounted him on the horse.
   他把小儿子举起来，让他骑在马背上。