Answer:
Kung hindi tayo marunong magpahalaga at mangalaga sa mga sinaunang kabihasnan sa daigdig ay maaaring masira at mawala ang mga ito sa atin.
The last one, A decrease in the price of racket ball rackets
Natural environment has the ability to gather some pollutants yet if too much then the environment could no longer handle it. A leaky sewage can pollute an aquifer with I. arsenic as the contaminant. Arsenic is a metalloid existing in the Earth's crush. Exposure is natural yet can be aggravated by the human activities.
You need to upload pictures of the sources so we can see them :)
