The term LIFE-SUPPORT SYSTEM refers to a system that provides essential life-sustaining services such as oxygen, food, water, and shelter. The crossword solutions for this term are ECOSPHERE (9 letters) and CEREALAISLE (11 letters). ECOSPHERE is an environment in which living organisms interact with each other and their surroundings. CEREALAISLE is a section of a grocery store where breakfast cereals are sold. Both of these terms are related to the concept of LIFE-SUPPORT SYSTEM as they provide essential resources for sustaining life.