The Horse and the Stag（在线收听）

    A very long time ago horses lived freely all over the world．One of these horses used to feed every day in a grassy meadow．No other animal used the meadow and the horse felt that it belonged completely to him．Then one day a stag came bounding over the hedge．He trampled carelessly all over the field，leaving deep foot marks and damaging the growing grass．The horse was very angry．He could not think of away to get his own back at the stag himself so he asked the man who owned the field to help him．“Of course I will help you，”said the man．“If you just let me put this piece of metal（a bridle）in your mouth and let me sit up there on your back，I will get my bow and shoot him for you．”
    The horse agreed and the man mounted on his back．But instead of riding off after the stag as he had promised，the man took the horse into his yard and set him to work．Ever since that time horses have obeyed men and worked as his slaves．Revenge is dangerous：it may hurt you as well as your enemy．Exercises：
    回答下列问题：
    ①Why was the horse angry one day？
    ②What do you learn from the story？