Answer:
They test or measure something.
Explanation:
Primary research articles report on research that has been completed. Therefore, a primary research article will review and analyze studies, and will state the research question and hypotheses of the studies presented. A primary research article does not test or measure anything, but will report on studies that do.
Light aka the sun I know for a fact
Answer:
The oceans are present on the 70 percent of the world but only 5 percent of the total oceans are explored yet.
There are many reasons of this problem but the most important is the hydrostatic pressure.
Hydrostatic pressure can be described as the pressure or weight exerted by the water on the object.
With every increase in 10 meters the pressure increase by 6.47kg (14.27lbs) each square inch of surface.
Due to extreme pressure, oxygen level in the cells of body fluctuates and person becomes unstable and can become unconscious.