力是_______对_______的作用。物体间力的作用总是_______的。在国际单位制中，力的单位是______。
物体 物体 相互 牛顿
My brother likes eating very much but he isn't very______ about the food he eats.
[ ]
A. special
B. peculiar
C. particular
D. unusual
急性腹膜炎早期呕吐原因是
A．神经性呕吐
B．反射性呕吐
C．肠梗阻
D．肠麻痹
E．肠痉挛
