This is the 144th most frequent Ukrainian word.
повністю
Completely.
In this sentence, "повністю" is used as an adverb to emphasize the completeness of understanding.
Він повністю зрозумів завдання.
He fully understood the task.
Here, "повністю" describes the extent of the destruction, indicating totality.
Будинок був повністю зруйнований бурею.
The house was completely destroyed by the storm.
In this case, "повністю" stresses the total agreement of the student.