Answer:
1. They answer the question ""Why Is Sleep Important?"" and are followed by text that provides further details.
Step-by-step explanation:
The article shows important information about sleep, what are the reasons why sleep is important in our life and how sleep is composed, what are its phases and its effects on the body and on the quality of life of the human being. All of this is divided into several subtopics that organize the article based on the information that each subtopic represents, but in general, we can say that the subtopics seek to answer the question "why is sleep important?" which in the end is the goal of the entire article.