D or c because one of them was agriculture that would be c but they also did the other two known as d but swaying towards c
Let's say that the land has pollution meaning there is trash everywhere and dead plants over there, with those types of pollution it will harm our water supply because sometimes the pollution can affect our water.
Clearing the lands that has pollution can do good for our water and our ecosystem. When we clean the lands, more plants are able to grow, animals build their homes there, etc. That means that the animals and/or plants have a drinking water that is safe to drink and isn't polluted because we cleaned the land and the water.
Keep America clean.
Hope this helped :)
Have a great day
i have fat weeny yumyumyum
By observing how seismic waves are absorbed and refracted, scientist have been able to work out where the properties of the earth change dramatically. our understanding of the internal structures of the earth and the size of its core is based on these observations.
basically:
size of core
structure of the earth I.e. the layers of the earth
and I think the last one is how the internal structure is changing? not sure on the last one but its still a solid guess.
