VOA慢速英语:Two Events Blamed for Dinosaur Deaths(翻译)

catastrophic – adj. of the nature of a catastrophe, a disaster

molecule – n. the smallest possible amount of a particular substance that has all the characteristics of the substance

layer – n. one thickness of something laid over another

rapid – adj. very fast

spike – n. a sudden, very fast increase in something

boundary – n. something that shows where an area ends and another begins

“one-two punch” – idiom phrase. getting hit, or punched, but one thing, and then another

clam - n. a type of shellfish that lives in sand or mud that has a shell in two parts (called bi-valves) and can be eaten cooked or raw

fauna - n. all the animals that live in a particular area, time or environment

impact – n. place where something hits another

extinction – n. when something has died out completely