A:took; make
B:take; made
C:took; made
二次函数y=ax2+bx+c的图象如图所示,在ab、ac、b2﹣4ac,2a+b,a+b+c,这五个代数式中,其值一定是正数的有( )
下列关于日本经济的说法,不正确的是( )