Sulfur oxide is a type of pollution that comes from - a reaction with oxygen
- burning gas in a closed space
- emissions from oil refineries
- open fields or construction sites

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave