Answer: B. meteorites, UV rays
The earth's atmosphere plays an important role in shielding the space rocks and meteorites enters inside the earth due to collision with the celestial body. Due to high heat and pressure in the mesospheric layer of the atmosphere these meteorites burned up before reaching the biosphere or hydrosphere system of the earth. The UV rays are protected from entering into the earth atmosphere by the ozone layer present in the stratosphere of the atmosphere. Both meteorites and UV rays can negatively effect the human population. Therefore, the atmosphere is an agent which provides protection against them.
A). Archaea Hope it helps you
Answer:

Explanation:
The frequency of a wave can be found using the following formula.

where <em>f</em> is the frequency, <em>v</em> is the velocity/wave speed, and λ is the wavelength.
The wavelength is 10 meters and the velocity is 200 meters per second.
- 1 m/s can also be written as 1 m*s^-1
Therefore:

Substitute the values into the formula.

Divide and note that the meters (m) will cancel each other out.


- 1 s^-1 is equal to Hertz
- Therefore, our answer of 20 s^-1 is equal to 20 Hz

The frequency of the wave is <u>20 Hertz</u>
<span>The characteristic not observed is the sun and planets rotate in the same direction. The planets in the solar system go around the sun. The sun is in a fixed position relative to planets. The time one planet takes to go around the sun is a year on that planet. the suns gravity keeps the solar system together and th planets revolving aroud it </span>