设X~N(3,32),则P(X2>9)=()。
A.2Ф(3)-1
B.1-[Ф(0)-Ф(2)]
C.0.5+Ф(-2)
D.1-Ф(2)+0.5
参考答案:C, D
解析:
According to the______ approach, language learning in real life differs from language learning in the classroom.
()用刀具从工件孔壁上切除微量金属层,以提高其尺寸精度和表面质量的方法叫什么加工方法
A.精钻孔
B.铰孔
C.锪孔
D.扩孔