Answer:
c. Observational studies have both independent and dependent variables.
d. Observational studies can be used to test hypothesis.
Explanation:
Observational studies are ones in which a researcher makes observations about his thoughts and views. He observes the risk and other effects before actual test takes place. This is usually the initial phase of research where observations are made for suitability of certain things that are to be researched. There is initial feasibility test conducted to identify whether the further research process is beneficial or not.
Geothermal energy is the energy given off by lava or magma. And since it is heat energy inside the earth it makes sense that it would have an effect on the environment
Answer:
massive war debts
Explanation:
the king wanted the colonies to pay for the war so he put taxes on everything
Yes! All the major mountain ranges, such as the Himalayas and the Rocky Mountains were all formed by tectonic plates colliding and pushing each other up, creating mountains.⛰