VOA慢速英语:地球上发现的最古老的物质：70亿年前的星尘

meteorite – n. a piece of rock from outer space

sample – n. a small amount of something that represents what it is like

curator – n. a person who is in charge of a museum

time capsule – n. a container filled with objects considered to be typical of a period in history and buried, so that it can be dug up and studied much later

interact – v. to act upon one another

baby boom – n. a large increase in the number of babies born in a particular place during a particular time

grain – n. a very small piece of a hard substance

conclusion – n. a decision made after a lot of consideration