__________ is added to the filtered water to kill harmful germs present in it.

Describe the threat to the beauty of the Taj Mahal.

Why does the increased level of nutrients in the water affect the survival of aquatic organisms?

What are the main causes of smoke?

Which problem arises by air pollution?

What is pollution?

What is air pollution?

Which gases are released by vehicles?

Which gas reduces the capacity of the blood to carry oxygen?

What is smog?

Which gases are responsible for acid rain?