3. C
4. D
5. No idea how to do this, sorry.
6. A
All these are correct I assure you. I took biology last year and thankfully kept my notebook. I had all the information I needed written down. For future reference I recommend taking notes, yeah it sucks but they help A LOT. It's your choice though. :)
Hope this helped. Have a great night!
C ........................
Answer:D) all of the above
Explanation:these are all correct because they all affect our environment
Answer: D
Explanation: the pioneer species is the first species to live in an environment
Yes, stimulating it with electrodes can potentially help improve mood and alleviate symptoms in those who suffer from treatment-resistant depression, among other ailments.