In a population,the condition at which the rate of addition of new members is more than the rate of individuals lost indicates:

If in a population,the number of organisms added by $B + I$ is less than the number of organisms lost by $D + E$ at time $t$,but the population size $N$ at time $t+1$ is $10$ times greater than the initial population size,which of the following characteristics can be inferred?

Read the following statements and determine how many of them are correct:
$(1)$ Population is the total number of individuals of a species in a given area at a given time.
$(2)$ Developed countries show a low birth rate.
$(3)$ An equal proportion of reproductive and post-reproductive age individuals indicates a stable population.
$(4)$ In the presence of limited resources,the growth curve is sigmoid ($S$-shaped).

The formula for exponential population growth is

Which of the following is true for $r$-selected species?

In which phase is the human population after the $17^{th}$ century?