Read the passage and answer the questions (Q. 6-8):
Earth is the only planet so far known with the suitable environment for sustaining life. Land, water, air, plants, and animals are the major components of the global environment. Population, food, and energy are the three fundamental problems facing mankind. Unemployment, inflation, crowding, dwindling resources, and pollution are all due to factors like increasing population, high standard of living, and deforestation, etc.