Answer: once again here ya go
Explanation:
The type of wave which needs a medium to travel are sound waves because they travel by oscillating electromagnetic fields
<h3>What is a Sound Wave?</h3>
This refers to the waves of refraction which is propagated by a plastic medium.
With this in mind, we can see that mechanical waves are the types of wave that needs a medium for propagation and a sound wave is an example of a mechanical wave because it travels by oscillating electromagnetic fields.
Read more about mechanical waves here:
brainly.com/question/9242091
Answer:
Sales tax is charged when a customer buys
Explanation:
While the Monroe Doctrine had sought to prevent European intervention, the Roosevelt Corollary was used to justify US intervention throughout the hemisphere. In 1934, President Franklin D. Roosevelt renounced interventionism and established his Good Neighbor policy for the Western Hemisphere.