def best_four_point_to_sell(self):
        """ 判斷是否為四大賣點

            :rtype: str or False
        """
        result = []
        if self.check_plus_bias_ratio() and \
            (self.best_sell_1() or self.best_sell_2() or self.best_sell_3() or \
             self.best_sell_4()):
            if self.best_sell_1():
                result.append(self.best_sell_1.__doc__.strip())
            if self.best_sell_2():
                result.append(self.best_sell_2.__doc__.strip())
            if self.best_sell_3():
                result.append(self.best_sell_3.__doc__.strip())
            if self.best_sell_4():
                result.append(self.best_sell_4.__doc__.strip())
            result = ', '.join(result)
        else:
            result = False
        return result
判斷是否為四大賣點

            :rtype: str or False