The principal reason for declining natural increase rates in less developed countries today is

Declining crude birth rates.

Explanation:

Birth rate may be defined as the number of births takes place per year per thousand of the population. The birth rate and death rate may change the population dynamics.

The developing countries shows the expanding population graph as they have more number of people of the reproductive age. The advancement in the medical field results in the decline birth rate that causes the decline of the nature resources.

Thus, the answer is declining crude birth rates.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

the correct answer in apex is tissue development, i know because i just had this question