A:What an
B:What a
C:What
D:How
若函数y= x-2x2-2x+c的自变量x的取值范围是全体实数,则c的取值范围是( )
读《槐乡五月》,下列写槐花饭的四个词中,如按词语表达程度的深浅排列,你觉得应该是______