Answer:
It is a noun phrase.
Explanation:
The noun phrases are "These three days", "their efforts to wipe away" and "Each decoration."
A noun phrase is a group of words that includes a noun, which acts as the head. The noun is modified by other word classes, such as adjectives or determiners.
While the verb phrases are "have been celebrating" and "are considered."
So, therefore, it is a noun phrase.
