Primate arms have one long bone, the humerus, in the upper arm above the elbow, and two thinner bones, the radius and ulna, in the forearm.

灵长类的上臂有一根长骨（肱骨），前臂有两根细骨（尺骨和桡骨）。

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Primate arms have one long bone, the humerus, in the upper arm above the elbow, and two thinner bones, the radius and ulna, in the forearm.

灵长类的上臂有一根长骨（肱骨），前臂有两根细骨（尺骨和桡骨）。

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