Mid-Autumn Day is Chinese traditional festival,I am so happy to have this day with my family; My whole family will stay together this night to celebrate it,enjoy the full moon and eat mooncakes.About the mooncake,My mother and I like mooncakes with egg yolk.At last I wish every family a happy day on this day.
翻译 ：
中秋节是中国的传统节日,我很高兴和家人一起度过这一天；我们全家将团聚于这一晚庆祝中秋并赏月、吃月饼.说到月饼,我和妈妈最喜欢吃带有蛋黄的中秋月饼.最后祝每一个家庭在这一天拥有幸福的一天.
PS:完全按照最简单的表达,没有用高级词汇和复杂句式,考虑到是小学6年级