A:鱼类→两栖类→爬行类→鸟类→哺乳类
B:鱼类→两栖类→哺乳类
C:鱼类 →两栖类→爬行类→哺乳类→鸟类
D:鱼类→两栖类→爬行类→鸟类
My mom ____ ____ and walked away.
Hainan is in the of China.
目前,我国许多地方启动了“单独二孩”政策,即一方是独生子女的夫妇可生育第二胎。此举引发了社会各界的关注和热议。该政策的实施( )
5×7____7×8 5+5+5+5____4×5
32-12____6×3 6×6____12
设M=2a-3b,N=-2a-3b,则M-N=( )