I think it's C i'm sorry if i'm wrong.
A simple stain is used to show that bacteria is present and what they look like opposed to other matter. a differential stain is used to separate organisms into groups.
The variable is y and y=2.
The type of sand dune that would most likely form if the sand supply is limited the wind direction is constant and vegetation is sparse would be a barchan dunes. It is a <span>crescent-shaped sand </span>dune<span> produced by the action of wind predominately from one direction.</span>
