肱骨干中段骨折反复手法复位易导致（）
A.桡神经损伤
B.正中神经损伤
C.尺神经损伤
D.腋神经损伤
E.肌皮神经损伤
参考答案：A
So difficult ___it to work out the problem that I decided to ask Tom for advice.
A．I did find
B．did I find
C．I have found
D．have I found
收运系统的优化分为几个阶段？
