Agenesis of ulna

• 尺骨发育不全

Agenesis of ulna的用法和样例：

例句

1. The ulna forms the chief articulation at the elbow.
   尺骨是组成肘关节的主要骨骼。
2. He hit his funny bone on the arm of the chair.
   他的尺骨神经碰到了椅臂。