Answer:
swinging from birches as a boy
Explanation:
Nouns are parts of speech used to identify and name a class of people, things, places. The nouns in this sentence are MOON which is the subject, CRATERS, and SURFACE. It can be easily identified if an article can be used before the noun
The abbreviation after a word in the dictionary tells you what kind/ part of speech the defined word is.
Hope this helps! :)