"This piece of jewelry comes from Paris."
Translation:Ce bijou vient de Paris.
A "morceau" is a part of something which doesn't apply here. The jewelry isn't taken apart. The problem is that "jewelry" in English is a mass noun, so in order to make it countable, we say "pieces of jewelry". In French, they have "bijou" (singular) and "bijoux" (plural). You can simply use "jewelry" for both of those in these exercises when translating from French. However, when translating from English, they provide "piece" or "pieces" so you can distinguish which French word to use.