想問三個，是不是名詞?

three---number;
The three Rs----reading,writing, and arithmetic,thought to be the most important parts of a child's education.
threesome---noun--a group of three people.
three-D---noun---to see the film in three-D.
But three-fold, adj, adv, -fold

量詞

是問“三個”這個詞嗎
如果是的話我記得是算量詞吧.....