Post_19.2.rb

def refine_pairs(list)

  new_sentence = []

  list.each do |sub_array|
    sub_array.each do |sentence|
      split = sentence.split(" ")
      new_sentence << split
    end
  end
  new_sentence
end

def matching_pairs?(list)

  list.each do |array|
    return true if array[1] == array[4]
  end
  false
end