2.There are many simple things that you can do on a daily basis in order to get fit. One excellent example is to climb the stairs instesd of using an elevator. The repeated use of the stairs helps strengthen leg muscles and also gets the heart beating faster. Another way to get exercise is to ride a bicycle to school or work if it is possible. If you take public transportation, you can get off at an earlier stop and walk the rest of the way. All of these little things add up. It just goes to show, you can get good exercise without making major changes to your life.
順便請問一下topic sentence 要怎麼分辨