Holes drilled several kilometers into Earth’s crust provide direct evidence about Earth’s interior in the form of
a.
seismic waves.
b.
rock samples.
c.
liquid iron.
d.
volcanic eruption.

B

Explanation:

They made a hole in the earth, and was only able to scratch the crust but found lots of rocks to help them learn about the earth  

vapour or gas assuming atmospheriv pressure

i think the answer is a, hope this : )