西门子PLC正常运行时,()指示灯()
A.运行;快闪
B.运行;亮
C.运行;慢闪
D.停止;亮
参考答案:B
Hi, Bob! I can't find my history book. () you () it anywhere
A.Did; see
B.Do; see
C.Have; saw
D.Have; seen
可信赖程度是根据统计结果求得,因此可信赖程度并不随样本量的增加而提高。( )