a long-separated old friend的用法和样例：
- The first time meet, can handclasp, have the old friend that meet again after a long separation only, ability can be embraced each other, flap the shoulder of the other side.
- Long separated for one year, return to the home of friend and mentor of Shenzhen, and new, old friend's friendship ties, incomparably glad!
- She's an old friend(= I have known her a long time).
- She's an old friend of mine(= I have known her for a long time).
- After a long separation, they held a glad meeting.