Look at the pictures below. Which of these pictures shows physical weathering processes by which soil is formed?
Picture 1 and Picture 3
Picture 2 and Picture 4
Picture 2 and Picture 3
Picture 3 and Picture 4

1. the is the thinnest part of the earth. 2. the is the thickest part of the earth. 3. what metals are mentioned in the text?

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Variety of living organisms; includes genetic, species, and ecological types.