Which of the following statements is/are correct? a. Valves open and close in response to pressure changesb. The chordae tendineae and papillary muscles stop the atrioventricular valves from everting in response to high ventricular pressure. c. The semilunar valves are closed by filling of cusps by backflow of blood. d. All of these statements are correct.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

get the total number of pieces of fruit and divide it by 4 to get the average. the result is the answer to the problem. 14 total number of fruits and there are 4 members. 14 divided by 4 is equals to 3.5.