Hi, friends!My name is Jason．I am 11 years old and I live in Chicago in the USA．There are many holidays every year,and，my favorite one is Thanksgiving(感恩节)．It is a family holiday．

    Thanksgiving comes on the fourth Thursday of November every year．There is no school on Thanksgiving Day．That's great!My family gets together on Thanksgiving Day．My brother will drive home from New York．We always have a big dinner．My mom makes a lot of delicious food．My sister always helps her in the kitchen．We have roast turkey,sweet potatoes,pumpkinpie(烤火鸡，红薯，南瓜派)and so on．Turkey is a must in my family．Before dinner we give thanks to everything

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    I love this holiday very much．It teaches me to be thankful in life．My favorite thing about the holiday is being with my family and having a great time with them．That is a very important thing of the holiday．

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燕子每年秋天都要从北方到南方过冬，鸟类科学家发现，两岁燕子的飞行速度v与耗氧量x之间满足函数关系v=alog₂ $\frac{x}{10}$ ．若两岁燕子耗氧量达到40个单位时，其飞行速度为v=10m/s，则两岁燕子飞行速度为25m/s时，耗氧量达到____单位．