小蜗牛问妈妈:“为什么我们从生下来,就要背负这个又硬又重的壳呢?”妈妈:“因为我们的身体没有骨骼的支撑,只能爬,又爬不快。所以要这个壳的保护!”小蜗牛:“毛虫没有骨头,也爬不快,为什么她却不用背这个又硬又重的壳呢?”妈妈:“因为毛虫能变成蝴蝶,天空会保护她啊。” The little snail asks her mother: “Why do we have to bear this hard and heavy shell from birth? ” Mum: “Because our body does not have the bones support, This shell protection! ”Small snail: “ The caterpillar is not bones, but also climb unpleasant, why she did not back this hard and heavy shell? ”Mum: “ Because the caterpillar can become a butterfly, the sky will protect She ah. ”