10. Which sentence uses incorrect parallel structure? A In the summertime, I love to go swimming, hike, or relax with a good book. В. For centuries, people have used energy from the sun to heat homes, to start fires, and to generate warmth in buildings. CO This book is useful for practicing language skills, learning new vocabulary, and understanding Spanish speaking cultures. D. By spending a year in Spain, you will not only enjoy living among a different culture, but also being able to travel easily throughout Europe. O