For a long time scientists have argued that the extinction of the dinosaurs was related to climate change. • • • Answer Choices A . Extreme changes in daily and seasonal climates preceded the retreat of the seas back into the major ocean basins . B. A simple climate change does not explain some important data related to the extinction of the dinosaurs at the end of the Cretaceous. C. The retreat of the seaways at the end of the Cretaceous has not been fully explained. D. The abruptness of extinctions at the end of the Cretaceous and the high concentration of Ir found in clay deposited at that time have fueled the development of a new hypothesis . E. Some scientists hypothesize that the extinction of the dinosaurs resulted from the effects of an asteroid collision with Earth . F. Boundary clay layers like the one between the Mesozoic and Cenozoic are used by scientists to determine the rate at which an extinct species declined. Reflection • Reflect on which questions in the passage were the most difficult for you and why. Note how often unfamiliar vocabulary made a question challenging. • Set a weekly goal to create and review vocabulary cards . Keep them handy during your study sessions so you can quiz yourself and reinforce your learning .
10
Made with FlippingBook - PDF hosting