磨削可获得很高的加工精度，其经济加工精度为（）。
A.IT10~IT9
B.IT9~IT8
C.IT8~IT7
D.IT7~IT6
参考答案：D
(2009天津河东一模)Some students are net surfing．which does great harm to their physical and mental health
A．addicted to
B．related to
C．addicting to
D．relating to
现在小学教师“所采用的教育观念”有什么特征？
