A:充分非必要条件
B:必要非充分条件
C:充分且必要条件
D:既非充分也非必要条件
Mrs. Green didn't talk to her husband for a long time, but now they ____ each other.
李林同学在不同季节的制作过程中,一定发生了化学变化的是( )
-2的相反数是( )