Before the establishment of veterinary schools in the United States, students studied veterinary science in Europe and had to complete a(n) *BLANK* before they could start their own practice. PLEASE HELP NO LINKS

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.