There is some water in a bottle near a big rock.A bird is very thirsty. He comes to the bottle and stands next to the bottle.But he can't drink the water，beacause the bottle's neck is very long. So he thinks and thinks，and then flies away. After some time，he comes[复习必备 | 海量免费学习视频资源学而思轻课APP”>>>点击了解] back with a small stone in his mouth.He goes up to the bottle and puts the stone into the bottle. He flies away and flies back again and again.He puts many stones into the bottle. The water in the bottle comes up to its neck and the bird can.