Which factor is a major contributor to outdoor air pollution?
a. radon
b. fossil fuels
c. ultrafine particles
d. carbon dioxide

Always use significant figure rules. remember that these rules apply to all numbers that are measurements. a car travels 6 miles north, 3 miles east, and then 2 miles south. what is the distance traveled? a.7 b.11

This group of organisms perform the process of ammonifcation. a. herbivores b. decomposers c. carnivores c. plants

The table below shows the elements that mainly comprise each of the four layers of earth: elements in layers layer main elements crust oxygen, silicon mantle iron, magnesium outer core iron, nickel inner core iron which of these elements make up the layer that is 0.2 to 1.1 percent of earth's total diameter?