某同学在百米比赛中，以6.0m/s的速度迅速从起点冲出，到50m处的速度是8.2m/s，在他跑的全程的中间时刻即t₁=6.25s时的速度为8.3m/s，最后以8.4m/s的速度冲过终点，他在百米比赛中平均速度的大小为____ m/s．

中国国土辽阔，区域差异显著，有学者将中国四大地理区域的自然差异进行概括和提炼，得出如下图结论，据此回答下列问题。

阅读短文，判断下列句子“正确”还是“错误”。

    Which Skirt to Wear?

    Tina is 8 years old, and follows her own ideas. When her parents tell her to do something, she always doesn't do it. Today, she will go to a friend's birthday party. She is now choosing skirt to wear. She has three skirts: a blue skirt, a white one and a yellow one. She asks her father, “Which one is the best?” her father says, “I think the blue one is the best.” Then she asks her mother, “Which one do you think is the best?” Her mother answers, “The white one, of course!” Tina says, “Thank you.” Then she puts on the yellow skirt and goes out.

请补写出下列名句名篇中的空缺部分。