Because augustine gained a better understanding of time, he was able to __

defend the church

"the sandy walls seemed to collapse in on themselves"

and

"the bloodshot waters seemed to have no bottom"

a. "to practice" is the best phrase to complete the sentence.

explanation:

during the summer, she likes to practice her soccer skills so that she is ready to play in the fall.

(note that : all the other options "the practicing of", "practice for" and "to do a practice on" are inappropriate as they make the sentence grammatically incorrect.)