Scientists evaluating the Cretaceous mass extinction have concluded that
A. an asteroid impact was probably the triggering event for the extinction.
B. only an extraterrestrial impact could have caused such a big extinction event.
C. climate change would not have been involved in producing the extinctions.
D. ecological factors such as disease and competition probably caused the dinosaurs to go extinct.
Answer:A
Scientists evaluating the Cretaceous mass extinction have concluded that
A. an asteroid impact was probably the triggering event for the extinction. B. only an extraterrestrial impact could have caused such a big extinction event. C. climate change would not have been involved in producing the extinctions. D. ecological factors such as disease and competition probably caused the dinosaurs to go extinct.