As we all know ,everything has two sides .SNS gives us a platform to know more friends ,and it is convinient for us to communicate with others .As it is a virtual world,we can talk with all kinds of people .What's more , there is no need to worry about what we should say and what we shouldn't .On the other hand ,we rely on SNS so much in our life ,we will lose some opptiunities to commnicate with people around us ,for example ,our friends,our teachers ,our parents and so on .Importantly ,we maybe become silent ,dont want to say a word in the real world .