The semilunar valves prevent the backflow of blood into the atria when the ventricles are contracting. the semilunar valves prevent the backflow of blood into the atria when the ventricles are contracting. a. true b. false

The shift of a vehicle's weight around its center of gravity is known as

Under the soviet system, the government a. controlled all forms of communication. b. allowed newspapers to print whatever they wanted. c. controlled editorials but not the reporting of news. d. encouraged access to a wide variety of news sources. select the best answer from the choices provided a b c d

Give an example of a trait that is controlled by more than one gene.