哺乳类是目前动物界最高等的类群,下列各项中最能体现哺乳动物高等的是
A:体内有膈
B:牙齿有分化
C:体温恒定
D:胎生、哺乳
No one hopes the two countries will be at ________ war, because ______ peace is what everyone wants.
—How's it going?
—___________.
如果+12=0,那么内应填的数是( )