刘权基

Even though we have never been to the Arctic， we can know what polar bears look like. Even though we arent in Brazil， we can feel the heat of the 2016 Olympic Games. Why？ We can see those things on TV. November 21 is World Television Day. It helps people in different countries understand each other better by exchanging their TV programmes.

Television is a common form of media which has a great influence on our life. In many countries， televisions even reach villages without electricity. They are powered by batteries there. Television can be an excellent teacher for the local people.

However， watching too much TV can be bad for childrens health. Scientists found that children who spend more than four hours per day watching TV are more likely to be overweight. Children who always watch violent acts on TV are more likely to be violent in the future. They are also more likely to be afraid of the world around them.