Which cloud is found ahead of a cold front, but behind the warm front?

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.

Which set of terms best describes a community of miners who live out in the countryside of west virginia and use specialized geographical equipment to analyze the composition of rocks

All phases of matter may have a fixed mass