n.大腿骨
The old man's son thus fell off the horse and broke his thighbone. 结果，塞翁的儿子从马身上摔下来把大腿骨跌断了。
The knee is the joint where the thighbone meets the large bone of the lower leg. 膝盖是大腿骨和小腿胫的连接处。
