Final answer:
The sentence should be punctuated with commas after 'soda' and 'not' to separate clauses in the sentence and set off the introductory phrase
Step-by-step explanation:
The sentence should be punctuated as follows:
Rocket finished his soda, and believe it or not,
balanced it on top of my eight-foot tower of cans.
The comma after 'soda' is necessary to separate the clauses in the sentence. The comma after 'not' is necessary to set off the introductory phrase 'believe it or not'.
Learn more about Punctuation in English sentences