now more and more people own televisions， which present a very vivid world to us. on television， we can watch exciting matches， see most of the places of interests without going there ourselves. from tv， we learn many things happening in the world.　television also plays an educational role in our daily life. children enjoy learning much interesting knowledge from tv. by providing various tv university courses， television offers various educational programs for different viewers.

　　however， television can also be harmful. it hurts our eyes. watching tv too much influences our sleep and work. now many students spend too much time on tv， which reduces their study time and does great harm to their health. in short， we should regard television as our assistant， not our master.