Answer:Dark matter is invisible and does not emit electromagnetic radiation. Dark matter is part of a theory that hypothesis the existence of a counterpart to the particles we know in physics, in order to balance the universe that otherwise would be largely unbalanced right now. However, the theory right now is not yet proven.
Explanation:done
The invention that allowed scientists to study cells for the first time is the Microscope
The correct answer is - Most killer whales congregate in the areas that are near the Arctic/Antarctic Circles.
The killer whales have a very large distribution, and they can be found in all oceans, apart from the Southern Ocean. It is noted though that the population density of the killer whales differs from place to place. The higher concentrations are found around the Arctic and Antarctic Circles, where there's cool rich waters, while in the lower latitudes they are much rarer. The reason for this probably lies in the fact that most of the animals that are considered to be the prime food source of the killer whales are living in this rich cold waters.
Answer:
they mutate and become immune to modern medicine
Explanation: