Both Radioactive dating of rocks retrieved from the world and Comparing cratering rates on one world to those on another.
Geologists can find the relative age of impact craters on a world because
the ones on top must be younger.
Scientists know the history of Earth's magnetic field because the magnetic field gets frozen into rocks, and plate tectonics spreads them out.
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Answer:
Most beaches get their sand from rocks on land. Over time, rain, ice, wind, heat, cold, and even plants and animals break rock into smaller pieces. This weathering may begin with large boulders that break into smaller rocks. Water running through cracks erodes the rock.
Rice prices must be kept within reach of the poorest people.
Floods. Monsoons are massive rainstorms which can often bring devastating floods to low ground. Hope I helped!
The two largest Metropolitionarea in Canada are Toronto and Montreal.