The initiative to have infants sleep on their back, rather than their stomach, has been associated with:

It has been associated with later crawling but not with later walking. The reality is that any baby who is a healthy child should be put to sleep on his/her back rather than on their stomach or sides by their mothers or whosoever takes care of them. This practice is really useful to lessen the dangers of sudden infant death syndrome.

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements

those characteristics are cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaptation through evolution. some things, such as a virus, demonstrate only a few of these characteristics and are, therefore, not alive