Most people have a cellphone. When you are walking on a busy street, you will see many people speaking on their phones. Many people say they can't imagine how they live without a cellphone. Cellphones play an important role in our daily life, such as keeping in touch with others, calling home or the police if there is any emergency . Although cellphones can help us a lot, we must think of others when we use them. Unfortunately, some people do not consider others when using their cellphones. For example, some cellphone users speak too loudly and discuss personal matters in public places. Some people make phone calls in the cinema. Some people talk for a long time on the phone while they are driving on the busy road. Someone's cellphone will ring during an important meeting. Many people complain about these bad manners. In their opinion, cellphone users shouldn't disturb others when they make a call. Then how to use a cellphone politely in public? The following rules will help you. When you're in a meeting, watching a movie or having a lesson, you'd better turn off your cellphone. When you get a call and you're with friends, try to make the call as short as you can. If you are waiting for an important call, then make sure that you tell others about this at the beginning of a meeting. It's rude to scream ( 尖叫 ) or shout on the phone. Make sure you will be heard only by the caller but not by the others around you. Besides, if possible, find a quiet place where you can talk in private.