One day, Allan and his friend Henry went swimming in a river. It was very hot. How happy they were in the river! After they got out of the water, they played games in the sun for a while.
    On their way back, Henry saw some flowers. He liked flowers very much and ran into the green field to look at them. Now Allan was walking by himself.
    Then he heard Henry calling out, "A snake（蛇）! Help!..."
    "What's wrong with you?" asked Allan.
    "A snake bit（咬）me in the leg. Come here!"
    Allan ran over and saw a small red wound（伤口）on Henry' s leg.
    "The snake was in the grass. I didn't see it."
    "Sit down quickly"! Allan told Henry.
    Allan put his mouth at the little red wound and began to suck（吸）at it. In this way he saved （挽救）Henry's life. "Oh, Allan, it's very kind of you to help me."
    "That's all right. We are friends and we must always help each other."

出门在网络平台上约辆车，有了闲置房可以网上短租……分享经济是指资源所有者将自己闲置的资源拿出来，供那些需要的人有偿使用，是互联网技术发展大背景下诞生的一种全新商业模式。以小猪短租、滴滴出行为代表的中国本土企业正领跑全球分享经济，未来5年中国分享经济年均增速将达到40％左右。分享经济迅速发展，是因为它（    ）

①哥伦布②麦哲伦③哥白尼④布鲁诺⑤达迦马

稳态的生理意义是（　　）