Probably erosion...either by wind, run-off water or a river that drains into the ocean near the ports.
Hope this helps!
Since the wheelbarrow is filled with soil, that adds more weight to it. Which means you would need to use more strength/force.
When the wheelbarrow is empty, it has less weight so you would use less force.
Answer:
When you scrape your knee, skin cells are replaced by meiosis.
Explanation: