The round stone structure honors people from the District of Columbia who died in World War One.

VOA: special.2009.05.25

And another person from Harvard, Philip Stone one of the parents of positive psychology was Philip Stone, who passed away two years ago, yesterday.

还有一位哈佛的教授，积极心理学的另一位父辈，两年前的昨天去世了。

哈佛公开课 - 幸福课课程节选

From time to time, he would visit the Judge in his big stone house.

VOA: special.2010.06.26

Union soldiers rose up from behind stone walls and fallen trees.

VOA: special.2009.11.05

From that stone you can form the perfect lens."

VOA: special.2009.07.18

Lithos comes from the Greek word for stone.

VOA: special.2009.09.02

Remnants of its 74 stone locks, as well as brick aqueducts that brought it water from the river,remain.

VOA: standard.2010.04.29

The impressive stone walls of the structure, he explains, have recently been rebuilt with financial support from the Spanish government, with the hopes of bringing more tourists to the town.

VOA: standard.2009.06.04