A stream that flows into two different rivers is part of two A reservoirs.
B. tributaries.
C. divides.

D.
watersheds.

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.

What type of weather does tropical continental air bring in summer? hot and cloudy cool and sunny hot and sunny cool and cloudy

Which of the following was a characteristic of a dromaeosaur? modified front claw grasping with their forelimbs both a and b none of the above