During a parenting group meeting, a mother reveals that she has observed her 6-year-old son playing with his penis during his bath. She asks the nurse how she should respond to the situation. What would be the nurse’s most appropriate response（）

A. "Avoid characterizing it as bad because that’s normal at his age. "

B. "If he does it often, you might consider disciplining him. "

C. "Ignore it and hope that he outgrows it. "

D. "Supervise his baths and encourage him to stop doing it. ”

骨肉瘤最好发的部位是

A．股骨和髂骨

B．脊柱和胫骨

C．胫骨和肱骨

D．股骨和胫骨

E．桡骨和股骨