Which of the following states has the highest population density?

What type of human population is represented by the following age pyramid?

The age pyramid with a broad base indicates:

$A$ biologist studied the population of rats in a barn. He found that the average natality was $250$, average mortality $240$, immigration $20$ and emigration $30$. The net increase in population is

Which of the following is not a population attribute?

List any four characters that are employed in human population census.