How is the chemical composition of sulfur dioxide, SO2, similar to that of sulfur trioxide, SO3? How is it different?

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world