11. All of these contribute directly to fertile topsoil except a. bedrock chemical reactions.
b. minerals supplied by rock particles.
c. decomposition action of fungi and bacteria.
d. earthworms' breaking down the soil.

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

Which of the following is an effect of the uneven heating of the earth by the sun? a sea breeze a land breeze a convection current all of the above

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.