One day. A baby snail （蜗牛）f that he had to carry a big and heavy shell （贝壳）at any time. He was very confused (困惑的),so he went up to his mother and asked , "Why was I born with a shell that grew so hard and heavy?" His mother said. "Because we don't have bones（骨头） to hold us up. We can only move slowly , so we need a shell to p us."
The baby snail asked again, "the caterpillar(毛毛虫)has (not) bones, either, and she can't move quickly. Why can she live without a shell?" The mother snail answered, "That's b a caterpillar will become a butterfly. She can fly high into the sky. The sky can protect her."
The baby snail had one (many) question, "But the earthworm(蚯蚓) moves l us. He has no bones and he can't turn into a butterfly. Why doesn't he carry a hard and heavy shell?" His mother said. "He can dig a hole and hide in the ground, and the earth can protect (he)."
The baby snail then cried, "We are so poor !We have no protection from the sky or from the ground!" His mother smiled at him, "That's why we have a shell. My dear, imagine that if we don't have the shells ,what will h to us ?Hot sun will dry out our bodies and we'll have (anywhere) to sleep. What's worse , we'll die in the heavy rain .How terrible it is! We don't depend on the sky or the ground for protection. We should depend (依靠）on o"
