Few Americans remain in one position or one place for a lifetime. They move from town to city to suburb, from high school to college in a different state, from a job in one region to a better job elsewhere, from the home where they raise their children to the home where they plan to live in retirement  . With each move they are forever making new friends, who become part of their new life at that time. For many of them summer is a special time for forming new friendships. Today millions of Americans vacation abroad, and they go not only to see new sights but also with the hope of meeting new people. No one really expects a vacation trip to produce a close friend, but the beginning of a friendship is possible. The word "friend " can be applied to a wide range of relationships ---- to someone one has known for a few weeks in a new place, to a fellow worker, to a childhood playmate, to a man or woman, to a trusted confidant  . From the passage it can be seen that a "friend" can be  _  .
a fellow worker a football teammate a boy or a girl all of the above