With golden sunshine and a gentle breeze  , autumn is the most beautiful seasons in the year. This is a great time to go outside and have fun. Go to a valley to see red maple trees , go and pick fruit in an orchard or find an open field to fly your kite in. However, for many high school students, these great activities may be just a dream. With plenty of work to do, they spend all their hours indoors, struggling for a high mark in their exams. Of course, study is one of the most important things for teenagers. But life is definitely much more than that. Sometimes we spend so much time studying that we forget how to make life wonderful. In doing so, we lose the real purpose of life --to be a valuable and happy person. To enjoy just how great it is to be alive, we have to put down our books and pens and look around us. Students, take some exercise to improve your health, talk with your parents and friends for understanding and walk around outside to refresh   your body and mind. Going out and enjoying the beautiful countryside often helps our creativity in our work. Chinese craftsman, Lu Ban created a saw to help woodworkers. But if he hadn't walked outside, he would not have been inspired by a kind of toothed   grass. We could also suppose if Newton hadn't rested under that apple tree, then he wouldn't have been hit by an apple, and his classic   theories would not have come out. Going out is not only a break from hard work, but a chance to add to life experience. So come on, give your brain a good rest. Step out of the books and get your bag ready for an autumn outing. We are sure you will get much more than knowledge from the exciting journey. The passage is developed mainly by  _  .
describing the beautiful scenery in Autumn pointing out the present situation of high school students making predictions reasoning and giving examples