discolouration的例句（discolouration在句子中的用法）

• Dual - action toothpaste with Xylitol and baking soda to remove stains and surface discolouration from teeth. 这种双重作用的牙膏,含有木糖醇和小苏打,能清除牙齿表层的污垢和污色.
• This discolouration is completely harmless. 这种变色是完全无害的.
• Discolouration of silver and basketry - inlaid silver artwares and the protection technology were studied. 研究了含有少量铜锌成分的银片或银丝笆镶嵌的银制工艺品变色及各种新工艺的防变色效果.