What are some methods used to extract petroleum and natural gas from the subsurface describe each

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Me with these questions if you’re it sure don’t answer

Which was most likely an effect on society that resulted from improvements in blood handling during world war i and world war ii?