A:CH3CH3+Cl2 →光照 CH3CH2Cl+HCl
B:CH2═CH2+HBr→CH3CH2Br
C:2CH3CH2OH+O2 →△Cu 2CH3CHO+2H2O
D:CH3COOH+CH3CH2OH ⇌△浓硫酸 H3COOCH2CH3+H2O
二次函数y=ax2+bx+c的图象如图所示,则一次函数y=ax+b的图象不经过( )