A 14-year-old female client in skeletal traction for treatment of a fractured femur is expected to be hospitalized for several weeks. When planning care, the nurse should take into account the client’s need to achieve what developmental milestone

A. Autonomy.
B. Initiative.
C. Industry.
D. Identity.

工件表面渗碳的目的是什么？一般哪些工件适于渗碳？