Final answer:
Marina's progression from a volunteer to a nurse over the years is indicative of a successful career in healthcare, demonstrating her commitment and experience in the field.
Step-by-step explanation:
Marina has been able to turn her jobs in healthcare into a successful career in healthcare. Starting as a hospital volunteer in high school, she progressed to becoming a medical assistant and then worked for 12 years as a nurse.
This journey reflects a significant contribution to the healthcare industry, where she likely gained a wealth of experience and expertise that could be applicable in various roles within the field, such as a leadership position in a hospital, a teaching role in a medical school, or even a research position in a healthcare organization.