Answer:
The function of the pleura is to allow optimal expansion and contraction of the lungs during breathing. The pleural fluid acts as a lubricant, allowing the parietal and visceral pleura to glide over each other friction free. This fluid is produced by the pleural layers themselves.
Answer:
A. a developing nation
Explanation:
Age pyramids are the age structure diagrams that represent the number and proportion of people at each age in a population. The base of the age pyramids represents the population in pre-reproductive age which is from 0 to 10 years. The overall shape of an age pyramid indicates if the population is increasing, stationary, or shrinking.
The age structure diagram for a developing nation has a broad base that tapers quickly towards the top. This means that a larger percentage of the population is in the pre-reproductive age group and reproductive age group with a smaller percentage of the population in the post-reproductive age. These countries have a great chance of future population growth.
