滚动轴承内圈通常装在轴颈上，与轴（）转动。
A.一起
B.相对
C.相反
参考答案：A
在下列的计算中，正确的是( )
A．2x+3y=5xy
B．（a+2）（a-2）=a2+4
C．a2•ab=a3b
D．（x-3）2=x2+6x+9
_____ does your brother watch TV? Every Saturday and Sunday.[ ]
A. How many
B. How often
C. How much
D. How long
