Final answer:
The nurse should first visit the adolescent with daily vomiting due to the immediate health risks of potential eating disorders. Subsequent visits should be prioritized based on the severity and immediacy of health risks.
Step-by-step explanation:
The community health nurse must prioritize client visits based on the urgency of each case. In the scenarios presented, the nurse should see the adolescent who has vomited every day for 3 months to lose weight for the summer first. This situation indicates a possible eating disorder, such as anorexia or bulimia, and presents a significant and immediate health risk due to potential electrolyte imbalances and dehydration. The other cases, while they also necessitate attention, do not appear to pose an immediate threat to the individual's health. The young adult with uncontrollable alcohol intake should be seen second, due to the risks associated with alcohol abuse and potential for withdrawal. The preschooler with hyperactivity and impulsivity comes next, possibly indicating a behavioral disorder such as ADHD but not an immediate danger. Lastly, the adolescent who has been truant from school requires intervention but is not in physical distress.