飞上天空是人类自古以来的梦想。最早借助“非凡的翅膀”帮助人们实现这一梦想的动力机是（    ）

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    I'm a lovely girl. You can call me Li Li. I like the blue sky and white cloud. I also like colourful flowers. I love my family. I love my father and mother. I go to school from Monday to Friday. Our home is near the school. We have a house. It is a clean and beautiful house. The house has three rooms. One is a living room. The other two are bedrooms. In the living room,  there is a table and six chairs. There are some flowers on the table. There is a garden in front of the house. I often play games and take pictures in the garden. Our house isn't big, but we like it.