Answer:
Classification system changes because the scientists find new evidence in their studies.
Explanation: The world is always changing and growing and dying as well as developing, so over time things change. For example, as you grow up do you stay the same? No, you notice the physical changes happening, well thats sort of like how the earth and its ways are always changing as well.
They break down the organic matter that has died so that the nutrients stored with in it can be reused.
The invading bullfrogs ARE HARMFUL. This is because, they cause decline in the population of the native species.
Decline in the population of the native species will throw the ecosystem into a condition of imbalance which will eventually affect all the living organisms that are living in that ecosystem.
