<span>Whatever the focus of the experiment is, plus any others factors that might influence the outcome of the experiment. If you are testing a new cancer drug, the experimental group and the control group must both be people with the same type of cancer, and both be a representative distribution of the population, all races, genders, ages, etc. You want the only difference in the two groups to be what you are studying, i.e. the effects of the drug.</span>
The correct answer for the statement “All the scientific
theories used to explain the formation of the solar system are non-testable”. The
answers outdated, imaginative and unacceptable are wrong. These theories are
not proven and yet are not tested due to the complexity.
Letter A: They travel in straight lines.
Because temperature sets a limit to how much water vapor can be in the air.
Answer:
The correct option is;
C) Equatorial coordinate system
Explanation:
The equatorial coordinate system is which has the most wide spread use in coordinate system for astronomy for mapping the location of celestial bodies such as stars by use of an imaginary projected celestial sphere or to rectangular coordinates with the Earth at the center. Extending the Earth's axis onto the celestial sphere is essentially the projection of the Earths axis outwards to intersect the sphere at the celestial poles.