Mateo’s parents are thinking about investing money to develop a new fusion power plant. which issue is most important to consider before making the investment? a)fusion has never been controlled, so how have they succeeded in doing it? b)the fuel is quite limited, so have they discovered a more common fuel? c)fusion has been generating electricity for decades, so why build another fusion power plant? d)fusion requires high temperatures and pressures, so how have they reduced the energy cost for it?

28. evolution

29. environment, survive, offspring  

explanation:

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.