Headphones take in sound waves. This is an example of ... A)reflection
B)absorption
C)transmission
D)refraction

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.

The half-life of a certain element is 100 days. how many half-lives will it be before only one eighth of this elementremains?