So if I want to use a string as we'll call it which is a word or phrase generally, they always go between double quotes, David hence the quotes around David, and they are double quotes not single quotes intentionally.

当我们要表示单词啊，词组啊，句子啊等等这样的东西时,就会用到字符串，它们位于双引号之间，也就是这里双引号之间的，是双引号，不是单引号哦。

哈佛公开课 - 计算机科学课程节选

One thing to notice is this part of the double helix that we'll call the backbone.

要注意的是,这两股构成双螺旋的链我们称之为主链

耶鲁公开课 - 生物医学工程探索课程节选

It's worth noting, however, that the rare double-call against Ovechkin a few hours later had nothing to do with yelling at an official.

WSJ: Ovechkin penalties spur Rangers' 4-1 win over Caps

Officials whistled Miller for a technical foul during Arizona's game against UCLA for arguing a late double-dribble call against Wildcats guard Mark Lyons.

NPR: Ex-Pac-12 Ref: I Was Trying To 'Lighten The Mood'

Officials whistled Miller for a technical foul during the semifinals of the Pac-12 tournament against UCLA for arguing a late double-dribble call against Wildcats guard Mark Lyons.

WSJ: Ed Rush Resigns as Pac-12's Head of Officials