下列各式中是二元一次方程的是(        )

    Cheongsam (also known as Qipao ), is a kind of traditional Chinese dress for women. It1from Manchu people of the Qing Dynasty(清朝) in the early 17th century.

    Once there was a young fisherwoman living near a place called Jingbo Lake. She made a living by fishing,2only problem was that when fishing she often felt bad because of her long wide clothes. Then an idea came into her3 — why not make a more comfortable dress to wear. Then she invented Qipao that helped herself fish 4.

    The5emperor(皇帝)who was in control of China at that time had a dream one night. In the dream, his dead father told him a lovely fisherwoman wearing a long dress, who lived by Jingbo lake, would 6 his wife. After that, the emperor sent some people to7that woman. At last, they found her8the place which his father told him. Then she became the emperor's wife,9her beautiful Qipao with her. Manchu women all liked Qipao and soon it became popular across China. Now it's also well-known all over the world. Not only Chinese women, but also women from foreign10such as Indonesia, are interested in wearing it.

This kind of traditional dress is made of either silk or cotton. And anyway, it becomes one of the symbols(象征) of China.

对夏朝王位世袭制代替禅让制的认识，正确的是

观察下面丰子恺的漫画《建筑的起源》，说明漫画内容，并写出两点启示。