HELP ASAP PLEASE Indoor air pollutants can be dangerous because the air pollutants stay in small space rather than circulating throughout the atmosphere. Which of these choices is an example of an indoor air pollutant?

A. Methane gas
B. Vehicle exhaust
C. Building materials
D. Industrial emissions

Galaxy whose shape seems different follow no set pattern are classified as

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?