<span>1. temperature
2.water purification
3. succession
4. alien species
5. conduct a survey of a species population in an ecosystem
6. adopt ecological conservation practices</span>
It has helped us by seeing what kind of things we can see with our eyes it also helps us by seeing mirco things like dirt
Your answer is d he saw brown algae
Answer:
"the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects."
To break it down, harmful chemicals and other things go into the air and that is called pollution. I believe that you can also pollute the water when you put items like plastic and such in it.
Explanation: