The concentration of dissolved oxygen $(DO)$ in cold water can go up to ......... $ppm$.

What are pesticides and herbicides? Explain giving examples.

The chemical entities present in the thermosphere of the atmosphere are

Which of the following diseases increases in prevalence due to the greenhouse effect?

The incorrect statement from the following is:

The pollutants which come directly into the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?