Answer:
muscular system and nervous system
Explanation:
I think ??????
Answer:
A
Explanation:
i go with A is that okay?
huh
Answer:
D. They define geological periods because scientists use them as reference points for tracking the history of the earth.
Explanation:
Catastrophic events related to changes in geological timeline are very useful in defining geological periods.
These events have very significant appearance in the geological record and can be used to determine the history of the earth.
The catastrophic events usually culminates into extinction cycles or termination of some organisms from the earth surface.
Geologists use these events that are often wide spread to delineate geological periods.
<span>The scientist is correct. It is part of under water mountain system, called mid-ocean ridge. The ridge consists of chains of mountains linked to one another with long valley. it also consists of openings. it causes for the seafloor spreading.</span>