阅读理解专项训练People are busy working every day. They do not have enough time to do exercise. So many people become too fat or too thin. We need to do exercise to keep fit.There are many kinds of exercise. Bending and stretching helps us move easily. Before we play ball games or swim, we shall do bending and stretching exercise first. This kind of exercise is sometimes called warm-up exercise. Running is also good exercise. If we cannot run fast, we can jog. Jogging means running slowly. Again
