Answer:
It's d
Explanation:
Scientists study dark matter by looking at how it affects visible matter.
It covers the younger part of the planet.
Answer:
wave changes its path from its initial direction so this phenomenon is known as Refraction of wave
Explanation:
When wave travels from one medium to other medium the due to change in the speed of the wave propagation it deviates from its initial path.
The deviation of the wave from its initial path is known as refraction of wave
Here we can see that wave incident on medium 1 with some angle with the boundary
Then it enters into other medium and then travels in other direction
So here wave changes its path from its initial direction so this phenomenon is known as Refraction of wave
No, there isn't. Please consult your doctor if this is the case with yours or someone you know.