Here is the item again:
While Kristy labored through another evening of incomprehensible accounting
homework, her roommate Bob read a sci-fi novel. And ate an entire bag of
potato chips.
You chose to use Punctuation Rule 8 to fix the problem:
Main Clause + Ø + Lonely Verb Fragment.
Here is the correction:
While Kristy labored through another evening of incomprehensible accounting
homework, her roommate Bob read a sci-fi novel and
ate an entire bag of potato chips.
Great job! You deserve those cyber chips!