Next autumn when you see wild geese ( 大雁 ) heading south for the winter flying in a V formation you might think about what scientists have discovered as to why they fly that way. As each bird flaps its wings , it creates an uplift ( 上升力 ) for the bird immediately following. By flying in a V formation the whole group adds at least 71% greater flying range ( 航程 ) than if each bird flies on its own. People who share a common direction and sense of community can get where they are going more quickly and easily because they are traveling on the push of one another. When a wild goose falls out of the formation , it suddenly feels the drag ( 累赘 ) and resistance of trying to go alone and quickly tries to get back into the formation to take advantage of the lifting power of the bird in front. When the head goose gets tired , it flies back into the formation and another goose flies to the front. It is wise to take turns doing difficult jobs whether it should be people or wild geese flying south. Wild geese honk ( 发出雁叫声 ) from behind to inspire those up front to keep up their speed. What can we learn from this? When a wild goose gets sick or wounded by gunshots, and falls out of the formation , two other geese will fall out with that goose and follow it down to lend help and protection. They will stay with the fallen goose until it is able to fly or until it dies, and only then will they go on with their own or with another formation to catch up with their group.