Answer:
A. 70 m OS the correct one
1-fixation ( Bacteria Converts nitrogen to ammonium so plants can use it )
2-nitrification ( bacteria changes ammonium to nitrates and plants )
3 - Assimilation (plants absorb nitrates it is then used for Chlorophyll..)
The frequency of the wave has not changed.
In fact, the frequency of a wave is given by:

where v is the wave's speed and
is the wavelength.
Applying the formula:
- In air, the frequency of the wave is:

- underwater, the frequency of the wave is:

So, the frequency has not changed.
Most earthquakes occur along or near the edges of the earth's lithospheric<span> plate. </span>