Select all of the organ systems that are directly part of our immune system?

Plz ! ive been stuck on this forever

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Explain how the political influence of african americans leaders became weaker.