In three to four sentences, explain how you would develop a long-term investing strategy to ensure that you will have a financially secure retirement.

An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ does a particular job in the body, and is made up of distinct tissues.

The most complex organisms have organ systems. ... One of the most important functions of organ systems is to provide cells with oxygen and nutrients and to remove toxic waste products such as carbon dioxide. A number of organ systems, including the cardiovascular and respiratory systems, work together to do this.