What does it mean that the right mouse button is context-sensitive?

Experimental data that is expressed using numbers is said to be

Which statement is true of web-based social media? a. they allow consumers to interact with and update content. b. they cannot be updated easily, as compared to print media. c. they are expensive to produce and maintain, as compared to print and television. d. they can exist independent of the internet.

What is one reason why indoor air pollution has become an increasing problem.