有着超过10年的在一线、二线及三线的IT支持经历，Jon Tydda现在为英国的制药研发提供专业知识。

With more than a decade of experience in first -, second -, and third-line it support, Jon Tydda now provides his expertise to pharmaceutical research and development in the United Kingdom.

youdao

陈家刚：对，我小时候在重庆，重庆也有三线，我的很多亲戚、同学家里都是三线的。

Chen Jiagang: Yes. I was in Chongqing when I was young. They also have a third line there. A lot of my relatives and classmates' families were all in the third line.

youdao

如它的名字一样，方阵由四组排成两线或三线的步兵组成一个空心正方形，所有人都朝向外侧。

As the name suggests, this is four two- or three-rank lines of infantry arranged as a hollow square, with everyone facing outwards.

youdao

sigma That is one pi orbital. There is one sigma, one pi and there is a second pi, and that is how we are getting the triple bond.

那是一个pi轨道，有一个，一个pi，还有第二个pi轨道，这就是我们如何得到三线态的。

麻省理工公开课 - 固态化学导论课程节选