Q. Which of the following is/are suspended particulate matter (SPM)?
1.Smoke
2.Dust
3.Vapor
How many of the statements given above are correct?
Answer: C
Notes:
Explanation: Suspended particulate matter (SPM) consists of solids in the air in the form of smoke, dust, and vapor that can remain suspended for extended periods and is also the main source of haze which reduces visibility.
Source: Shankar IAS

