Which is the most difficult to fossilize?
a) fish
b) mammals
c) plants
d) snails

How do you date a sample of rock that you suspect as being one of the earliest on earth

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

Identify the structures ! 20 points