_2. The stars and the sun and the moon guided early explorers.
Where to put the commas?

The stars, and the sun, and the moon guided early explorers.

Explanation:

The literary device in which the same conjunction is repeated multiple times is called the polysyndeton. The conjunction most often used like this is and.

This is an unconventional use of conjunctions. It would be more natural to write the given sentence like this:

Since this use is not conventional, there are no strict rules regarding punctuation. In literature, there are versions with and without the commas before the conjunctions. If you need to put the commas somewhere, you'd put one before each conjunction. The given sentence would look like this:

how to build a tree house

atmospheres is the answer to your question.

explanation: