Other sites let you use the Google Authenticator app to generate the six-digit number. The app generates a different six-digit number for each connected site, and these numbers change every 30 seconds. With the app, you don't have to wait a few seconds to receive a text message.
Factors that cause population growth include increased food production, improved health care services, immigration and high birth rate. These factors have led to overpopulation, which has more negative effects than positive impacts. Keep Learning.
The term population growth refers to how the number of individuals in a population increases (or decreases) with time. This growth is controlled by the rate at which new individuals are added to the population -- the birth rate, and the rate at which individuals leave the population -- the death rate.