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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def join_strings(key, value, fmt, meta):
 # pylint: disable=unused-argument """Joins adjacent Str elements in the 'value' list."""

    if key in ['Para', 'Plain']:
        _join_strings(value)
    elif key == 'Image':
        _join_strings(value[-2])
    elif key == 'Table':
        _join_strings(value[-5])