在带电作业中,电流的防护要严格限制流经人体的稳态电流不超过人体的感知水平()之外。
A.500μA;
B.1000μA;
C.1350μA;
D.1500μA。
参考答案:B
What surprised me most was _________ to meet his girlfriend again.
A.not his allowing
B.his not being allowed
C.his being not allowed
D.his having not been allowed
价值流图的绘制步骤是什么?