<em><u>ANSWER:</u></em><em><u> </u></em>
<em><u>The </u></em><em><u>ans </u></em><em><u>is </u></em><em><u>true!</u></em>

<h2>Fixation</h2>
Nitrogen in its gaseous form (N2) can’t be used by most living things. It has to be converted or ‘fixed’ to a more usable form through a process called fixation. There are three ways nitrogen can be fixed to be useful for living things:
<h3>Biologically: </h3>
Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants. Legumes (such as clover and lupins) are often grown by farmers because they have nodules on their roots that contain nitrogen-fixing bacteria.
<h3>Through lightning: </h3>
Lightning converts atmospheric nitrogen into ammonia and nitrate (NO3) that enter soil with rainfall.

The answer is to this question is A
Précipitation évaporation transpiration condensation percolation précipitation runoff.
D.exotic animal trade contributes to reemergence of diseases more than the appearance of new disease<span />