Question

Which of these sentences from the passage expresses an opinion?
Sleep is defined as the period of rest when a person is inactive and unaware of his or her surroundings.
Children and adolescents need approximately eight to nine hours of uninterrupted sleep every night to be at their best during the day.
People need to realize how important sleep is and what sleep deprivation can do to people.

Answer 1

The sentence that expresses an opinion is: People need to realize how important sleep is and what sleep deprivation can do to people. All the sentences of the passage state the information that stands a fact or universal truth, while the last one stands as conclusion based on the listed facts in previous sentences, so it can be considered as an opinion of the author.