支配臂和前臂背面全部伸肌的神经是（）。
A.尺神经
B.桡神经
C.腋神经
D.正中神经
E.髂腹下神经（T12～L4）
参考答案：B
---Have you seen Bill recently?
--- Oh, no! Nobody knows ______ he is! Everyone is looking for him.
A．where
B．what
C．who
D．how
