下列属于复杂反射的是（ ）

根据材料内容，选择正确答案。

    We see many animals, like rabbits(兔子), bees, dogs, birds, sheep……but do you know how these animals say things? First, let's see a rabbit. When a rabbit sees something dangerous, it runs away at once. When it runs, its tail(尾巴) moves up and down. When others see this, they run too.

    Many other animals use this kind of language. When a bee has found some food, it goes back to its home. It cannot tell other bees where the food is by speaking to them, but it does a little dance in the air. This may tell other bees where the food is.

    Some animals say things by making sounds like a man does. For example, a dog barks(吠) when a stranger(陌生人) comes near. Some birds can make several different sounds, each with its own meaning. In a word, every animal has its own language.

各顶点都在方格纸格点（横竖格子线的交错点）上的多边形称为格点多边形．如何计算它的面积？奥地利数学家皮克（G•Pick，1859～1942年）证明了格点多边形的面积公式S=a+$\frac{1}{2}$b﹣1，其中a表示多边形内部的格点数，b表示多边形边界上的格点数，S表示多边形的面积．如图，a=4，b=6，S=4+$\frac{1}{2}$×6﹣1=6.

武王伐纣的性质是（    ）