他们是笔友，从来没见过，但已经通信数年了。帮忙翻译成英语

They are pen pals, and had never seen, but has communication for several years.

They are pen pals. They have never met each other, but they have been communicating with each other by letter for years.

They are pen-friends,but they have never met each other.They have written to each other for years.

They are pen pals, though haven't met before, for ten years.

They are pen pals, and had never seen, but has communication for several years.

They are pen pals for years but never see each other.