Scientists believe that humans arrived on Earth during the _______ Period?

Question

A. Quaternary
B. Tertiary

C. Cretaceous

D. Triassic


What drives currents deep in the ocean?

A. Wind
B. Increased temperatures

C. Differences in water density

D. Decreased salinity

I think the first one is A.
and the second one A.
Am I right??

Answer 1

Unfortunately, the correct answer isn't provided for the first question. Quaternary and Tertiary are outdated terms, although they still are widely used in Geological Literature. The correct answer is the Neogene Period. Since that isn't an answer you have to go with A) Quaternary, which is the last 1.6 million years of the Earth's history. The answer for the second question is C) Differences in water density, since cold water sinks and stays down there until more cold water displaces it. This process is constantly moving cold water from the polar regions toward the equator along the bottom of the ocean. Also, warm water moves toward the poles, so it could be answered as B), but that answer doesn't account for cold water currents.

Answer 2

No scientists worth their salt will tell you that humans "arrived" on earth. Where did they arrive from?

As for the answers to the other questions: Why not do your homework yourself? If not, there's always wikipedia...

Answer 3

How about you do your own homework? If you are sophisticated enough to post the question online, then you should be able to do your own research.