Which phrase best describes scientific theories? a. explain few observations b. serve as speculations c. are never proven d. cannot be replaced

A. Explain few observations. A scientific theory explains why something behaves the way it does and is usually backed up by different sources. They are not speculations and can be proven. Those which are speculations and are not proven are called hypothesis. A scientific theory can also be replaced, if it is found that it does not produce valid results, or if a better theory is proposed which is made of one or more old theories.

voluntary muscles are controlled by the cerebellum.