WILL GIVE To explain the reasons for immigration, demographers use .

O surveys

O the “push-pull” theory

O birthrates and death rates

O life expectancies
i think its the the “push-pull” theory
but im not sure.

In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. the production of sterile male ligers is an example of read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. the production of sterile male ligers is an example of a postzygotic barrier the founder effect sympatric speciation a prezygotic barrier

Abrief, "first-step" presentation of a work to be completed is called a

In ancient egypt, the pharaoh collected from the peasant farmers. a. oil b. gold c. lumber d. taxes