Investigator williams arrives at a suspected crime scene, then sprays the area with a substance and turns off all the lights in an effort to find bloodstains invisible to normal eyes. what material, equipment, or technique is he using?

He is using luminol.

Explanation:

Luminol is a chemical substance that helps find bloodstains that are invisible to normal eyes. Luminol is a chemical substance that reacts to blood and other substances. The chemical reaction it has with blood it’s that it makes the substance more fluorescent. That is why is use in this type of scenes, because it makes it easier to locate and see all the possible bloodstains. Dry blood reacts better than fresh blood.

Luminol

Explanation:

I took the test, but also the notes say  "With this test, a luminol reagent is sprayed on surfaces or stains to see if blood is present.  If it is, the bloodstain will emit light or luminescence. "

c- dynamic stretching

no, because those are both different running competitions. while distance runners train their legs and their lungs to run long amounts of time, the sprinters are training their legs and their lungs to give all they have in the little amount of area they need to cover. the brain also plays a huge part in all of this.

the brain is the only thing in your body that sends messages to your body telling you to run. if you are a long distance runner and you have the mind set of a sprinter, you will not get anywhere. if you have a long distance mind set and you have to run 200m in 20 seconds then you will not make it in time.