July is coming. People all around the world are talking about their____(vacation). Parents would like____(help) their children relax.____ (luck), they have two months off. Some people enjoy quiet life, so many of ____(they) stay at home watching TV, using computers and so on.____some spend time differently. My pen pal Tony ____ blonde hair is a boy from the US. He says that ____(America) like going to the countryside. Just like his big family, they often go to a farm. There, some can feed animals, some can play and ____(other) can watch____ nice sky and rivers. They can also taste delicious food. They are quite _____(interest) in the life there.

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（Ⅰ）化C₁，C₂的方程为普通方程，并说明它们分别表示什么曲线；

（Ⅱ）若C₁上的点P对应的参数为t=﹣ $\frac{\pi }{2}$ ，Q为C₂上的动点，求线段PQ的中点M到直线C₃：ρcosθ﹣ $\sqrt{3}$ ρsinθ=8+2 $\sqrt{3}$   距离的最小值．

一物体做平抛运动，下列四幅图中能正确反映物体水平速度（甲）和竖直速度（乙）随时间变化关系的是（　　）