-----Jack，could I use your bike？I need to go to the market this afternoon.

-----______！I won't use it.

A．Go ahead

B．Don't mention it

C．Take it easy

D．It's up to you

关于骨肉瘤，下列哪项是正确的（）

A.好发于股骨下段和胫骨上端干骺端

B.局部肿胀、疼痛，有时表现类似急性炎症

C.X线摄片上可见骨质破坏，骨膜下新骨形成和日光放射状阴影

D.经摄片诊断，应立即行高位截肢术

E.预后差