想象一篇没有换行符的很长的文章。就像
sentence 1. sentence 2. sentence 3. sentence 4. sentence 5. sentence 6. sentence 7.
sentence 8. sentence 9. sentence 10. sentence 11. sentence 12. sentence 13. sentence 14.
sentence 15. sentence 16. sentence 17. sentence 18. sentence 19. sentence 20. sentence
21. sentence 22. sentence 23. sentence 24. sentence 25.
我想在每 5 个句子后添加换行符。或在每 5 个“。”之后
我怎样才能做到这一点 ?