What defines a great circle?

定义大圆的是什么？

You have been sent through the great circle.

你们已经被大圆门送来了。

We are all connected in the great circle of life.

在这个庞大的生命圈里我们是互相关联的。

I knew I had gone in a great circle and I was lost.

我明白我转了个大圈子，我迷路了。

It USES the great circle formula to compute the travel mileage.

它采用大圈公式计算旅行里程。