A:x2-4=(x+2)(x-2)
B:1-(x+2)2=(x+1)(x+3)
C:2m2n-8n2=2n(m2-4n2)
D:x2-x-=x2(1-+)
x+ax5x∈R展开式中x3的系数为10,则实数a等于( )
Hundreds of football fans were t____ away from the stadium because it was full.
下列有关文学常识的表述,正确的一项是( )