—I'm trying to keep my cool because we've been together ________ three years.
A:in;in
B:for;in
C:in;for
D:for;for
已知x=1是方程x2+bx﹣2=0的一个根,则方程的另一个根是( )
下列关于细胞生活所需物质和能量的说法正确的是( )