Soil as a result of wildfires in grasslands.

a.

improves

b.

degrades

c.

is unchanged

d.

is lost

The answer is A. After everything has burned away the nutrients from the ash are absorbed, making the soil better for regrowth.

4) repetitive change

Mars and earth have quite a few things in common. both are  terrestrial planets, both are located within the sun’s  habitable zone, both have  polar ice caps, similarly  tilted axes, and similar  variations in temperature. and according to some of the latest scientific data obtained by rovers and atmospheric probes, it is now known that mars once had a  dense atmosphere  and was covered with  warm, flowing water.