They stay with my family two days in Shijiazhuang.[ ]
A. on
B. to
C. for
答案:C
将抛物线y=3x2向左平移2个单位,再向下平移1个单位,所得抛物线为( )
A.y=3(x+2)2-1
B.y=3(x-2)2+1
C.y=3(x-2)2-1
D.y=3(x+2)2+1
TPM活动中,要求对设备进行彻底“6S”的目的是什么?