input: 
  def extract_verbs(sentence: str) -> list:
      """Extracts and returns the list of verbs from a given sentence using the NLTK library.
      >>> extract_verbs("The cat jumped over the moon.")
      ['jumped']
      """
  
output:     import nltk
      nltk.download('punkt')
      nltk.download('averaged_perceptron_tagger')
  
      words = nltk.word_tokenize(sentence)
      tagged = nltk.pos_tag(words)
      verbs = [word for word, pos in tagged if pos.startswith('VB')]
      return verbs