I have a dog. Its name is KoKo. It has a big head and two big eyes. It's white and black. It has two big ears and a small nose. KoKo can run fast(快的)and swim. It likes eating meat. It can play with me. I like my dog. KoKo is my good friend.
已知函数f(x)=2-x,x≤2x-22,x>2,函数gx=b2-f2-x,其中b∈R,若函数y=f(x)﹣g(x)恰有4个零点,则b的取值范围是( )
某人因外伤成为“植物人”,处于昏迷状态,饮食也只能靠人工往胃里注食,呼吸和心跳靠自己,那么,他的中枢神经系统中仍能保持正常功能的部分是( )