Based on the context you've provided, the most appropriate words to fill in the blanks would be:
"Even when the overall text structure of an informational text is not sequential, certain events may be shown in time order. The reader may rely on dates or transition words to reassemble those events and determine how they interrelate."
So the filled-in sentence would read:
"Even when the overall text structure of an informational text is not sequential, certain events may be shown in time order. The reader may rely on dates or transition words to reassemble those events and determine how they interrelate."