In Numbers^x, Gerunds^x, Abstract nouns^x

Hello, this is my first post here, I like to know these words kilometer centimeter Are those words noun if they are standing alone ? if it's, what kind of noun it's, proper noun or abstract noun or etc ? After that, I want to indentify the part of speech of the following setence by using the...

There are only a limited number of abstract nouns for which this pattern applies. From the examples below, you can pretty much guess the kind of noun that is needed. The "of ---ing" phrase forms an appositive to the noun in question. Among the possibilities are "habit", "custom", "tradition",...