A drink cover for covering a mouth of a can or a bottle is formed of a flexible sheet material. The indicator element is manufactured from a substantially transparent material provided with an informative indicator pattern. Then, the sliding surface which is the front side of the valve plate is covered with the sliding layer formed of a sintered copper alloy containing Cu and Sn as principal components and the remaining components as the remainder. An information processing apparatus having the printed circuit boards has means for selecting a combination of the EMI reducing circuits which allow the minimum EMI emitted for the apparatus. The method includes displaying guide information when entering a user key pad setting mode, determining a designation range for the user key pad according to a user interaction inputted based on the guide information, computing a key arrangement of the user key pad in response to the determined range, and configuring the user key pad according to the computed key arrangement.