If attacked, the wagons could quickly form a circle for defense.

VOA: special.2009.03.30

So, we can say that a circle is a good approximation for a 1 s wave function.

所以我们说一个圆是,对1s波函数的好的近似。

麻省理工公开课 - 化学原理课程节选

We formed like a surfer circle,held hands, sort of like a funeral ceremony for the departed dolphins."

VOA: standard.2010.08.04

A Washington landmark, Dupont Circle, became ground zero for a massive, friendly snowball fight that was organized on Twitter and other social networking sites.

VOA: standard.2010.02.07

He qualifies exhumations as a humanitarian act that allows families to close what he calls the circle of pain and mourning in which they have been caught for a quarter of a century, and says it was unthinkable as recently as a few years ago that investigations into war crimes would have been allowed in this country.

VOA: standard.2009.12.18