A portion of the barley is roasted to give Guinness its dark colour and its characteristic flavour .
A portion of the barley is roasted to give Guinness its dark colour and characteristic taste .
A portion of the barley is roasted to give Guinness its dark colour and characteristic taste .
改写这句话: A portion of the barley is roasted to give Guinness its dark colour and its characteristic flavour . 输出: