Answer:
question 9
Step-by-step explanation:
Question 19:
Definition of uniformitarianism: the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.
Hence the answer is Geologic processes we see today were also at work in the past.
Question 20: Answer is Radioactive substances undergo decay at a predictable rate. Only with a predictable rate can the age of rocks be determined by its radioactivity.
Question 21: Answer Tectonic forces deformed the rock.
Question 22: the sudden appearance of organisms. In the Phanerozoic eon is known as the time period with an abundance of plants and animal life as animals first developed hard shells preserved in the fossil record.