Which quartz sample has probably undergone abrasion in a stream for the longest period of time?

1)A
2)B
3)C
4)D

It would probably be A.

Explanation: Abrasion means scraping or wearing away. Therefore the correct sample is probably going to look smaller, smoother, and more even from all the scraping of the river currents.

Hope that helps!

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

the correct answer should be false

{apex}