Why is astronomy considered an observational science? It is hard to do experiments in astronomy.

Scientists do not have a sample of other stars or galaxies that they can put in a bottle.

Astronomers don't like telescopes.

It is impossible to do theoretical science in astronomy.

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

Which organelle plays a role in intracellular digestion?

Tom wants to conduct a scientific study but he needs to finish by the end of the school year. what practical way could tom work around this limitation and be successful in his study?