Seismic Waves!
Hope this helped :-)
Human activities that increase the greenhouse effect are burning of fossil fuels and reducing the amount of trees on our planet increase the gases of the greenhouse affect. also cows release the gas methane when they fert which is a greenhouse gas.
Astronomy can best be described as a "<span>a. study of objects beyond earths atmosphere", although the subject of astronomy can be much more complicated. </span>
