Have you ever been surprised by the trend that young people would rather stay indoors than go outside?     1     This phenomenon (现象) has drawn great public concern. To this phenomenon, different people come up with various ideas. Some people are in favor of the idea of keeping indoors. They point out the fact that       2    . 待在家里可以省很多钱. They also argue that they would rather save time to do other things than waste time to walk around.     3    . However, other people stand on a different ground. They consider it is harmful to stay indoors. They firmly point out that people would be in poor health if they always stay indoors. Most young people watch TV, play computer games and search the Internet when they keep indoors.     4    . 年轻人需要做锻炼，享受新鲜的空气. As far as I am concerned, it does harm to stay indoors for a long period. We ought to enjoy the beautiful scenery outside and talk with people.     5    . Though with the wide use of the Internet, we can almost do everything at home, we have to enjoy our outdoor lives.