Trả lời:
1. Soil contamination.
2. Factory chemicals or sewage and other wastewater.
3. Yes, it is.
4. For thousands of years.
5. When contaminated land is returned to use as buildings or agriculture land.
6. A way of stopping or reducing land pollution.
7. To reduce our need for new ones.
8. We need to clean up many contaminated sites.
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OK BẠN NHÁ^^