This discolouration is completely harmless.这种变色是完全无害的.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.Discolouration of silve...

n.变色，褪色，污染...

discolouration的音标：discolouration的英式发音音标为：[dɪskʌlə'reɪʃən]discolouration的美式发音音标为：[dɪskʌlə'reɪʃən]...