input: Write a python function to convert paragraphs to sentences.
  assert convert_paragraphs_to_sentences("This is the first sentence. This is the second sentence. This is the third sentence.") == ["This is the first sentence", "This is the second sentence", "This is the third sentence"]
  assert convert_paragraphs_to_sentences("Hello world. How are you?") == ["Hello world", "How are you?"]
  assert convert_paragraphs_to_sentences("One sentence.") == ["One sentence"]
output: def convert_paragraphs_to_sentences(paragraph):
      import re
      sentences = re.split(r'(?<=[.!?])\s+', paragraph)
      return [sentence.strip() for sentence in sentences if sentence]