Answer:
This is because in biology, energy is transferred from organism to organism and some energy is lost along the way. Each energy transfer results in a loss of energy, so that energy is always at a lower level and can never be returned to its original high energy level. On the other hand, chemical elements can form products, then that reaction can be reversed and break back down into reactants. Additionally, the law of conservation of matter says that matter can't be created or destroyed, only transferred from one form to another.
Emigrated means they exited so due to the high amounts of pollution all the animals left which cause a population decrease
Answer: Subsistence agriculture.
Explanation: Subsistence agriculture is a type of farming in which farmers cultivate and grow food crops and livestocks to meet their needs and that of their family.
In this type of agriculture, farm products is aimed to survival and it doesn't involve use of large-scale irrigation, chemical fertilizer, or machinery and technology.
Be there for them and let them know they're not alone.