What most effectively displays the concept of comparison and contrast?

It's to know your purpose before you read something because a purpose can:

What is the source of tension in this excerpt? ellery searching everything insects filling the light fixtures ellery standing on the desks louise carpenter whispering

While in the capitol, peeta proves to be both an advantage and a disadvantage to squad 451. do you think peeta is more beneficial or more detrimental to the squad? why? your response should be four complete sentences or longer.