Now to start with, the plasmid is usually shown in a diagram like this as a circle.

首先要说的是,质粒通常用图中这个环形来表示

耶鲁公开课 - 生物医学工程探索课程节选

You've got negative charge in motion, and it's in a circular orbit.

负电荷在运动，它们处在一个环形的轨道中。

麻省理工公开课 - 固态化学导论课程节选

I just wanted to get her on the subway and she, too, she did mention I want a round trip, she wants to be able to come back from Park Street Station so where is the option that just says one way or round trip?

我只想让她乘上地铁，她也是，她提到她想要一个环形旅行，她想,从Park，Street地铁站返回，但是哪里有一个选项,来说明是一个单线的还是环线的？

哈佛公开课 - 计算机科学课程节选

The first step is we had to be able to take this circular DNA and cut it to create a site for our new gene to be added.

第一步是切割环形DNA,以创造出一个整合新基因的位点

耶鲁公开课 - 生物医学工程探索课程节选