How does one determine when an ecosystem is unbalanced

Which greenhouse gas is emitted when burn fossil fuels for energy? a.nitrogen b.oxygen c.carbon dioxide d.helium

Fruit bats in central america eat bananas and other fruits. banana plants rely on bats for pollination. what would be the most likely consequence on the banana crop if fruit bats were eliminated from the area? the banana crop would increase because bats would stop eating the crops. the banana crop would decrease because bats would no longer pollinate the crops. the banana crop would remain constant because bees would replace the bats. the banana crop would remain constant because the plants would adapt using asexual reproduction.

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above