A:if it were
B:would it be
C:had it bee
D:should it have bee
墨子周游列国时带了三大车竹简,出行不便。导致这一现象发生根本变化的发明是( )
在(x+1)(2x2﹣ax+1)的运算结果中x2的系数是﹣6,那么a的值是____ .
如图为人体内肺部的气体交换图,请据图回答:
函数y=ax2+1与y= ax (a≠0)在同一平面直角坐标系中的图象可能是( )