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It's a hot summer. A thirsty crow(乌鸦) rests in a tree in a desert. He wants to drink some water. After a long time flying, he finds a house at the foot of the mountain. The crow is excited to find a glass jar with a little water inside the house. However, he can't reach the water because the jar is tall and big. There are many pebbles beside the house. He has an idea. He keeps collecting pebbles and dropping them into the jar. Finally, the water is close to the top of the jar. He drinks the water happily. What a clever crow!