Which layer is made of solid nickel and iron?
a.
crust
b.
mantle
c.
outer core
d.
inner core
i think it is either the inner core or the outer core.

Marianne is comparing two animals: a fruit fly and a fruit bat. she asks, "do a fruit fly and a fruit bat share a common ancestor in their evolutionary history? " according to evolutionary theory, what is the answer to marianne's question?

How are mutations continually being generated in a population (what are some of the causes of mutatuions? ) explain

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.