Which of the following is not a component of photochemical smog?

During a school field trip,a botany student visited a beautiful pond in a village and collected some plants. He observed that villagers were washing clothes there,and household waste was spoiling its beauty in some areas. After a few years,he revisited the pond and found it completely covered with algae,emitting a foul smell,and the water had become unusable. Can you describe this condition of the pond?

Which one of the following is not a common component of photo-chemical smog?

Write a short note on the effect of Global warming and Greenhouse effect on environment.

When a huge amount of sewage is dumped into a river,the $BOD$ will

What will happen in the future if the current rate of air pollution continues?