– He always shouted and laughed when I was singing in the yard.

-- _______. He’s only playing himself!

A．Watch out

B．Just ignore him

C．Don’t mention it

D．No way

出现陡壁型直方图，表明( )。

A．作频数分布表时，分组过多

B．心理因素的影响

C．过程中存在自动反馈调整

D．工序异常