Science question ! explain your answer. you!

which rock layer/fossil would be considered the oldest?

fossil 1
fossil 2
fossil 3
fossil 4

Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health?

If a volcano’s magma is high in silica, the volcano will probably a. erupt quietly. b. remain dormant. c. erupt explosively. d. produce dark-colored lava.

The caste system in india was used for what purpose? a) to ensure that all people had an adequate income b) to prevent the rich from taking too much power c) to provide social control and conformity according to one’s birth d) to draft a military capable of defending india from mongol invasion