Good evening, everyone! Today, I'm very glad1a speech2name is "My Dream". We know everyone has his or her own dream. Some people want to be basketball players because they are good3sports. Some would like to become4 because they like to stay with children. Do you know5I'm going to be when I grow up? I like cooking,6 I want to become a good cook. I think I must have great7 cooking food. I'd like to ask everyone to taste my food. I also like seeing their smiling faces after8the delicious food. However, it's not so9to be a good cook. I decided to learn 10things about cooking from now on. I will work hard for my dream. I'm sure I will succeed (成功) one day.

1958年的《中华人民共和国户口登记条例》规定“公民由农村迁往城市必须持有城市劳动部门的录用证明或户口登记机关准予迁入的证明”，这改变了“五四宪法”关于居民“自由居住和迁徙”的规定，形成了城市和农村户口的“二元结构”模式。这一变化（     ）

在1：500000的地图上，实地距离为20千米的两城市在图上的距离是（　　）