判定通电直导线周围磁场的方向,通常采用()进行判定。
A.左手螺旋定则
B.安培环路定理
C.右手螺旋定则
D.楞次定理
参考答案:C
----Can you attend tomorrow’s meeting?
----I am sorry , but I will have too much work__________.
A.to see to to come
B.seeing to come
C.to see to coming
D.doing to come
水文地质类型复杂、极复杂矿井没有设立专门防治水机构和配备专门探放水作业队伍、配齐专用探放水设备的属于一般事故隐患