Question

explaining how earthquakes reveal earths interior
how do earthquakes help geologists understand earths interior?
during an earthquake, geologists use a machine called a □ to study seismic waves.
p waves can pass through both solid and molten rock, but s waves can pass only through □ rock.

Explanation:

For the first blank, geologists use a seismograph to study seismic waves during an earthquake. For the second blank, S - waves (shear waves) can only pass through solid rock, as they cannot travel through liquids or gases.

Answer:

First blank: seismograph; Second blank: solid