The question below comprises four scattered segments of a paragraph. Identify…

Correct sequence by content:

• "Nobody knows why we sleep, but we all need to." — This sentence introduces the topic and belongs at the start.

• "There are no rules about how much sleep is necessary but the average adult sleeps for 7 hours 20 minutes." — This general statistic follows the introduction and sets the context for more detailed adult figures.

• "About 8% of adults are happy with five hours or less and 4 % want ten hours or more." — These specific adult percentages naturally elaborate on the prior average figure.

• "Babies need fourteen to eighteen hours sleep whereas the elderly need less than they did when young but often take a nap during the day." — This age-related detail broadens the discussion at the end, moving from general adult information to differences across life stages.

Concise explanation: Start with the general introduction, give a general adult statistic to set context, elaborate with specific adult percentages, and finish with age-related information to round out the topic.