如图所示，将小球a从地面以初速度v₀竖直上抛的同时，将另一相同质量的小球b从距地面h处由静止释放，两球恰在 $\frac{h}{2}$ 处相遇（不计空气阻力）．则以下说法正确的是（   ）

    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?

已知700K时，N₂+3H₂  2NH₃   ΔH＝－Q kJ/mol，现有甲、乙两个容积相等的密闭容器。保持700K条件下，向密闭容器甲中通入1molN₂和3molH₂，达平衡时放出热量 Q₁kJ；向密闭容器乙中通入0.5molN₂和1.5molH₂，达平衡时放出热量 Q₂kJ。则Q、Q₁、Q₂的大小关系是（      ）

生物进化的主要证据是（　　）