A:1
B:6
C:12
D:14
用反证法证明命题:“若整系数一元二次方程ax2+bx+c=0a≠0有有理根,那么a,b,c中至少有一个是偶数”时,下列假设正确的是( )
My daughter usually gets up at 6: 00 the morning, but Sunday morning she gels up at 8: 00.