Overgrazing is a cause of desertification, so c.
<span>1. A hydrogen fuel cell is more efficient than a combustion reaction because very little of the released energy is released as HEAT.
We need more energy emit as light and less heat. Lesser the heat more the efficiency.
2. </span>when used at home a fuel-cell illuminates the need for <span>an electrical grid</span> because the cell is portable.
As said, it is portable.
<span>Performance = 70.443 + 4.885 * (time)
P = </span><span>70.443 + 4.885 * 2.6
P = 70.443 + 12.701
P = 83.144
P - 16 = 83.144 - 16 = 67.144
Her score is 67.</span>
