answer to each of the questions.

Lives.

However, on social networking sites, most users have about 150 friends. If these numbers are correct, then friendship means different things in different situations. One of the reasons for having more online friends than real friends at a certain point in time is that online friendships do not require much time and energy: it is easy to accept friendships and keep them forever. Another possibility is that it is difficult to say 'no' when somebody asks us to be their friend online, even if we feel we don't really know them. The fact that they ask us suggests that they do consider us a friend, which is a nice feeling. Alternatively, they may be 'collectors' of online friends and just want to use us to get a higher number of friends and appear to be popular. Online friendships are quite easy, but in the real world decisions about friendships are harder to make. There are no rules about friendship. There are no guidelines about how to make friends, how to keep friendships going, and how to finish friendships if we want to move on. People have very different opinions about this: some people would die for their friends and they value them more than family. Others say that friends are temporary, only there to help each other until they are no longer needed. If people with such different views become friends, this can lead to problems. Because of these different definitions of friendship, it is easy to be unhappy about our friendships. We may want them to be deeper or closer, or we may want to have more friends in our lives. Sometimes we simply do not have the time to develop our friendships, or we fear we have left it too late in life to start. If we move to another country or city, we have to find ways to make new friends again. This dissatisfaction shows us how important friendships are for most of us. We should not think that it could be too late to build friendships. We also need to understand that the need to be around other people is one that is shared by many. Therefore, we should not be too frightened about starting to talk to people who in the future may become our friends: it is likely that they too would like to get closer to us. Remember what people say: strangers are friends we have not met yet.

Air traffic controllers must usea form of communication that is universal understood because a A B C pilot’s understanding of instructions is critical. D