The rock cycle is the process by ehich new rock is made from old rock
Answer:
The Precambrian history of Earth is difficult to determine for all of the following reasons except e. There are few useful index fossils in the Precambrian record .
Explanation:
Precambrian history
Precambrian history is difficult to study as there are relatively low Precambrian fossils and most of the Precambrian rocks have metamorphosed and ,
there are few useful index fossils in Precambrian record as it is well known the evolution of life on earth was not very predominant in Precambrian time.