Correct answer only !

as we have learned sound travels at different speeds through different mediums.

put the states of matter in order from fastest to slowest velocity.

Some examples you could look up on-line so I don't have to:

Speed of sound in sea water . . . 1,531 m/s

Speed of sound in iron . . . 5,130 m/s

Speed of sound in air . . . 340 m/s

This gives us

fastest . . . medium . . . slowest

solid . . . . . liquid . . . . . gas

it would be kevlar ^^

here are some information of the future of geothermal energy:

-the future of geothermal energy can pretty much be summed up with a single word: more

-scientists plan in going deeper than 120 meters

-we are hoping that one day, we will get all of our energy from renewable energy sources such as geothermal energy

hope this !