元朝的大都既是政治中心，又是闻名世界的商业中心口意大利旅行家马可·波罗的《马可·波罗行记》就描述了大都的繁华景象。

    Every school has its own rules. How many1are there in your school？ At some schools, the students 2 to wear uniforms on school days. But many students don't like to wear uniforms. They think the uniforms are the ugliest 3 in the world. But the school don't allow students to wear 4 own clothes at school. So some students draw cartoons or some famous singers on their 5. They think it is very6that everyone wears the same. It is very unfair(不公平的） that teachers and students are wearing7. But most of the students 8the rules. What do you think 9 it? Do you 10your school uniforms?

3×6____12

25____5×5

4÷2____8

12÷3____3