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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 wind_shear(shear: str, unit_alt: str = 'ft', unit_wind: str = 'kt') -> str: """ Format wind shear string into a spoken word string """

    unit_alt = SPOKEN_UNITS.get(unit_alt, unit_alt)
    unit_wind = SPOKEN_UNITS.get(unit_wind, unit_wind)
    return translate.wind_shear(shear, unit_alt, unit_wind, spoken=True) or 'Wind shear unknown'