4. Fill in the blank with an appropriate word or phrase to improve parallelism for each sentence.

a. The fitness instructor ran a marathon, , and won a weight-lifting contest.

b. The following people will be receiving computer upgrades this year: Leo Vasquez, Chief of Operations; Carla Willoughby, Quality Assurance Director; and Lucy Alva, .

c. Shoe cobblers liked stiletto heels because the tips needed frequent repair, doctors warned against stiletto heels because they caused sprained or broken ankles, and .