Investigators have arrived at a crime scene and are ready to search for evidence. What needs to happen next? A
They should ask a judge for a search warrant to be able to explore.
B
They should only search for evidence at the primary crime scene.
C
They should map out a grid to systematically look for evidence.
D
They should only search for evidence if a case looks complicated.

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

What is the problem in this article? what solution does the article propose?

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).