A report says school maths standards in England have failed to improve in the last 30 years, ______ than those in mid-1970’s, when only 20% of the students could pass maths exams.

A．no better

B．not better

C．no worse

D．not worse

检查轴套孔中心线与轴套端面垂直度一般用（）借助涂色法或塞尺。

A.直角尺

B.百分表

C.塞规

D.配合轴