The ozone layer is the answer!
Answer:
Two ureters.
These narrow tubes carry urine from the kidneys to the bladder. Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop.
Explanation:
Answer:
The correct answer is - As a person ages, scoliosis may develop resulting in an abnormal spinal curvature and shorter stature.
Explanation:
Scoliosis is a condition in which spine curvature towards the sides takes place before the puberty during growth period or spurt normally. The cause of this condition could be muscle dystrophy or palsy and similar condition.
This affects the stature of an individual but not affected by age as it remains constant normally after development or growth till puberty. All other conditions are associated with the short stature and influenced by the age.
2. High birth rate, zero death rate, high immigration, zero emigration
This is because birth rate and immigration increase population size, and death rate and emigration decrease population size, so maximizing the former and minimizing the latter are ideal
