Answer: The blood enters the left atrium, through the mitral valve then into the left ventricle
Explanation:
Answer:
Pollution, crimes and overcrowding.
Explanation:
Lack of family planning is responsible for the rise of population. It brought many adverse changes in the environment such as pollution, crimes and overcrowding etc. Rise in population causes unemployment that leads to crimes in the society. It also produces pollution due to more human activities such as emission of fossil fuels and more industries should be built to provide basic needs to more population. Rise in population causes agricultural to be converted into residential area that leads to decrease food production.
The atmosphere is composed of many different gases. Oxygen is 20.95% contained in the atmosphere.
