Their motivation is that they can sell the wood, and earn money.
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.
Hope it helps
Fuel, i believe is the answer
Answer:
fastest in rivers, slowest in groundwater
Explanation:
For rivers, lakes and groundwater, self-purification is fastest in rivers and slowest in groundwater.
When groundwater becomes contaminated, it tends to remain contaminated because the dissolved oxygen levels are low or non-existent.