It's a little puzzle piece that says when the green flag is clicked and this is kind ; of like the beginning of a program; when you double click an icon on your desktop this is how something like that is implemented; it's listening for that double click, it's listening for that green flag.

是一小个按钮，它的意思是,何时点击绿色旗帜,这就好比开始运行程序;,当你双击桌面上的图标,就开始执行操作,桌面的图标需要双击，绿色小旗也等待点击来执行命令。

哈佛公开课 - 计算机科学课程节选

Because I keep counting down each time around-- mostly I've got to unload this candy which is driving me nuts, so-- thank you.

因为我每次循环b减了,我一共要执行这个循环b次,所以这里我们一共执行了3b次基本操作。

麻省理工公开课 - 计算机科学及编程导论课程节选

b times. So I've got to go 3 b steps. All right I've got to go through the loop b times I've got three steps each time, and then when I pop out of the loop, I've got two more steps. All right I've got the initiation of answer and the return of it.

好，我一共执行了b次循环,每次循环内部进行了三次基本操作,当跳出循环后还有两个基本操作，因此这个初始的答案就是,2+3b次基本操作,来完成这个循环。

麻省理工公开课 - 计算机科学及编程导论课程节选