If the birth rate in a population is 40, and the death rate in that population is 15, then the population will be experiencing growth. The growth will be 25 on every 1,000 people. If this trend continues for longer period, then the population will start to become younger and younger, making the basis of the population pyramid wider, while the top part of it smaller and smaller. This demographic situation in modern times seems to be present only in the less developed countries, with the majority of the transitioning countries having much decreased population growth, and the more developed countries having more deaths than births, thus being aging populations.
Answer:
The main function of the lungs is the process of gas exchange called respiration (or breathing). In respiration, oxygen from incoming air enters the blood, and carbon dioxide, a waste gas from the metabolism, leaves the blood. A reduced lung function means that the ability of lungs to exchange gases is reduced.
The two semilunar valves, the pulmonary and aortic valves, are closed, preventing backflow of blood into the right and left ventricles from the pulmonary trunk on the right and the aorta on the left.
Maybe that if they stop swimming they won’t die? Not sure if that’s helpful but it’s a suggestion. Here’s a link about sharks-https://g.co/kgs/jVvFkF
The lining of the uterus, and the fallopian tube.
