Astudent hypothesizes that the bubbles on this water plant are oxygen gas (o2). however, identifying a gas as o2 with direct evidence requires many kinds of equipment. which observation would provide indirect evidence that the bubbles are not o2? a. the production of bubbles by the plant when it is in darkness b. a change in the size of the plant's leaves over time c. the estimated volume of all bubbles produced by the plant d. a description of the color and shape of the plant's leaves

the device is called “ rocket engine”

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.