如果直线l₁∥l₂，则∠α=____．

风力发电前景广阔，但风力发电场占地较多。下图是“我国风能资源分布示意图”，读图完成下列各题：

读“五带划分图”回答．

完形填空A
    Once upon a time, there was a lazy poor man living in a small house with spider webs(网) on the walls and mice running around. People1coming into such a dirty place and the poor man was lonely and2 every day. He thought he was unhappy 3poverty(贫穷).
    One day, the poor man dropped in on4wise old man and asked him for advice about5his life. The old man gave him a vase and said, "This is a magic vase6will bring you 7.
    The poor man looked at the vase 8 He wondered 9a vase in his poor house.10 ，he didn't want to throw away such a beautiful vase, so he brought it home and put it on the table. "11not right for something 12beautiful to be empty." The poor old man looked at the vase and thought. Then some flowers 13into it. That made the vase even14 "How can I have the vase next to a spider web?" he continued. At this, he started to clean the house and paint the walls. His house turned 15 a comfortable place immediately.
    The old man cheered up and he suddenly realized why he was unhappy. From then on, he worked hard and his life got better and better.

某实验小组用“落体法”验证机械能守恒定律，在用正确的方法进行实验后：