Ahypothesis is a. always correct b. determined before experimentation begins c. the experimental factor that changes in response to a change in the independent variable d. testable and falsifiable

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.