当你的手指无意间碰到灼热的物体时,会立即缩回手臂.请根据示意图判断神经冲动的传导方向是( )
Hello. I am Amy. I am eight years old. Today is my birthday. Look, I have a birthday cake. I have juice and rice for dinner. And I have many gifts, too. A red toy monkey, two new bags and five storybooks. I am so happy today.
先化简,再求值:(3﹣x)(3+x)+(x+1)2,其中x=2.