下列分解因式正确的是( )
A:x3﹣x=x(x2﹣1)
B:x2﹣1=(x+1)(x﹣1)
C:x2﹣x+2=x(x﹣1)+2
D:x2+2x﹣1=(x﹣1)2
- How many ____ (rulers/ruler)?
-____ (One/Two) ruler.
下列说法正确的是( )