Question

read the passage and correct the the words that dont match the others in the list.
most athletes are always looking for a new challenge to test their limits and developing their skills. for many, triathlons offer the right mix of mental and physical training. in a triathlon, athletes compete in swimming, biking, and a run, all in the same race.
beginners usually start with the sprint triathlon, in which athletes swim for one quarter of a mile, bike for ten miles, and run for five kilometers. for more serious competitors, there are other triathlons of varying lengths. the hardest and most extreme is the famous ironman triathlon, which requires racers to swim 2.5 miles, go biking 150 miles, and run an entire marathon, one right after the other.
success in this sport requires athletes not only to master the physical demands of the race but also training their minds as well. focus on the course and transitioning quickly from one part to another are crucial in achieving the lowest possible race time. the triathlon may be a difficult and demanding sport, but the feeling of accomplishment after finishing one is worth the effort.

Explanation:

1. "developing": Parallel structure error; should match "looking" (base form after "to").
2. "a run": Inconsistent noun form; should match gerunds "swimming, biking".
3. "training": Parallel structure error; should match "to master" (base form after "not only to").
4. "are": Subject-verb agreement error; singular subject "Focus" needs a singular verb.

Answer:

1. Change "developing" to develop
2. Change "a run" to running
3. Change "training" to train
4. Change "are" to is