Which of the following is NOT a characteristic of weathering and erosion?

a
caused by the pull of gravity
b
occurs only with water
c
caused by burrowing animals
d
occurs naturally

Which of the layers of the earth has the following three characteristics? i. it is a solid outer layer. ii. it is between 3 and 30 miles thick. iii. it is separated into plates. a. the outer core b. the inner core c. the mantle d. the crust