Plaque

匾額 /匾额

biǎn'é

(flat, thin piece of clay, ivory, metal, etc., used for ornament)

斑點 /斑点

bāndiǎn

(accumulation of biofilm, or bacteria, on teeth)

牙斑

yábān

(accumulation of biofilm, or bacteria, on teeth)

紀念碑 /纪念碑

jìniànbēi

(piece of flat metal with writing on it to remind people of a person or event)