title: Remove negative words from sentences
body: <p>The <code>neutralize</code> method below is intended to remove negative words from sentences.</p>
  
  <pre><code>def neutralize(sentence)
    words = sentence.split(' ')
    words.each do |word|
      words.delete(word) if negative?(word)
    end
    words.join(' ')
  end
  
  def negative?(word)
    [
      'dull',
      'boring',
      'annoying',
      'chaotic'
    ].include?(word)
  end
  </code></pre>
  
  <p>However, it fails to remove all of them. Whereas I expected to get:</p>
  
  <pre><code>"These cards are part of a board game."
  </code></pre>
  
  <p>I got the following result:</p>
  
  <pre><code>neutralize('These dull boring cards are part of a chaotic board game.')
  # =&gt; "These boring cards are part of a board game."
  </code></pre>