In paragraph 5 thoreau speaks out against the modern inventions of his day, such as a. the telegraph and the railroad. b. refrigeration and cars. c. the telephone and the railroad. d. none of the above

technical documents should be clear and precise. basically, clarity is the key element in a successful technical document.

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.)