One drawback of GPS technology is that it: A. may infringe on people's privacy.
B. shows us places we've never seen.
C. costs a lot and is difficult to use.
D. is unreliable and you can get lost.

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.)

the following what exactly?