input: Write a function to take a list of strings and generate a list of lists of words from the strings. The returned list should have the first word for each string followed by following words for each string.
  
  assert get_word_lists(["Hello world", "This is a test"])==[["Hello", "world"], ["This", "is", "a", "test"]]
  assert get_word_lists(["Python rocks", "C is solid"])==[["Python", "rocks"], ["C", "is", "solid"]]
  assert get_word_lists([])==[]
  assert get_word_lists(["SingleWord"])==[["SingleWord"]]
  assert get_word_lists(["Short string"])==[["Short", "string"]]
output: def get_word_lists(strings):
      return [s.split() for s in strings]