周围神经损伤后，从神经纤维长入终末器官到效应器官出现生理功能，一般约需（）
A.1周
B.2周
C.3周
D.4周
E.5周
参考答案：B
Most electronic devices of this kind, _______ manufactured for such purpose, are tightly packed. [ ]
A. that are
B. as are
C. which is
D. it is
决定粉尘粒子在呼吸道阻留部位的主要因素是（）
A.尘粒的直径
B.粉尘的水溶性
C.粉尘的脂溶性
D.浓度
E.尘粒比重
