International Operations works with the Department of Homeland Security and other U.S. agencies to vet participants in International Visitors Program events nationwide.
Life cycle. Life cycle means the stages a living thing goes through during its life. In some cases the process is slow, and the changes are gradual. Humans have various steps during their lives, such as zygote, embryo, child and adult. The change from child to adult is slow and continuous.
Mathematically, life expectancy is the mean number of years of life remaining at a given age, assuming age-specific mortality rates remain at their most recently measured levels. It is denoted by , which means the mean number of subsequent years of life for someone now aged , according to a particular mortality experience.