Sample Response:
Bacteria are helpful because they produce oxygen, which our bodies need to breathe, and they help us to digest the food we eat. Bacteria are also helpful because they are used in medicine to help us overcome disease. Bacteria are harmful because they can cause tooth decay and illnesses that can be either common or quite serious.
This is a sample response, so it's 100% correct. Peace!
Maybe because of global warming and the glacier water melting makING it bigger and deeper. (I hope this is the answer you are looking for)
Precipitation.....................
I'm almost positive it's B (<span>B. It must be compacted and/or cemented</span>, but it's been along time since this subject..... Hope this helped.
The most likely answer is A) A drastic reduction in the animal population due to migration or death by starvation.