A:神经元
B:精原细胞
C:口腔上皮细胞
D:精细胞
如图:二次函数y=ax2+bx+c的图像所示,下列结论中:①abc>0;②2a+b=0;③当m≠1时,a+b>am2+bm;④a﹣b+c>0;⑤若ax12+bx1=ax22+bx2,且x1≠x2,则x1+x2=2,正确的个数为( )
He doesn't have much time ____ (listen) to music from Monday to Friday.