posted by Bob on .
Which of the following describes the slowest change on earth's surface?
A) Gravity pulls an area of wet soil and rock downward in a landslide
B) An earthquake releases energy that built up below Earth's surface
C) Lava explodes from a volcano on an island
D) A canyon forms as water carries away weathered bits of rock
Which process takes the longest time?
A) The wind erodes a sand dune on the beach
B) A maple tree grows to be 100 feet tall
C) High mountains are eroded to gentle hills
D) A river floods and changes its course