病人表现为双足各种深、浅感觉均受累，常局限于肢体末端，呈手套或袜套状，其神经病变部位应当在（）

A.神经末梢

B.神经干

C.神经丛

D.神经根

E.传导束

I ____ to reach the manager for the last two hours but the line is always busy. [ ]

A. tired

B. have tired

C. had tired

D. have been trying