1) F (Tien Shan is a mountain range)
2) T
3) F
4) F (Karakum is a desert)
5) T
Challenges for growing crops are you don't know if it will be successful, you have to have enough water, the dirt has to be fertile, and the weather may affect how the plant grows.
Answer:
a. They must be present in a large geographic area.
Explanation:
Index fossils can be used to determine the age of a rock strata with great precision, but they must be scattered over a large geographic area to be able to be used reliable for this type of measurement. Index fossils typically indicate a certain type of paleoenvironment belonging to a very specific prehistoric period and their formation coincides with the age of the rock layer.
