An area that was covered by a glacier
Primary succession is a method of bringing about fertility in infertile land that can not be cultivated. This method usually involves plant species known as "pioneer species", that do not rely heavily on soil nutrients but add nutrients to the soil. The land under the glacier is likely to be void of nutrients and infertile, so primary succession will be needed there the most.
Answer: The number of blocks holding up the end of the pan
Explanation: Denise wants to test how a hill's slope can affect erosion. So, the number of blocks holding up the end of the pan should be her variable.
<span>Thiobacillus denitrificans is a specialized species of bacteria that obtains its energy from carbon dioxide and inorganic compounds such as nitrogen in its environment. It is used in bioremediation of groundwater that contains excess nitrate. Thiobacillus denitrificans help bioremediate groundwater by denitrification.</span>
