If you've ever been using some program, you did something completely innocuous, pull something down from a menu, click a button, you didn't do anything wrong and yet all of a sudden the thing just starts hanging there or you get a little spinning beach ball or the hour glass or whatever it is.

如果你之前在用一些程序，做一些无伤大雅的事情，拉下一个菜单，点击一个按钮，你没有做任何错误的事情,突然间有东西开始一直运行,或者一个沙滩上的小球旋转,或滴漏或是别的什么。

哈佛公开课 - 计算机科学课程节选

Notice at the bottom right here, we have all these different icons.

注意右下方有，一些不同的按钮。

哈佛公开课 - 计算机科学课程节选

So, we approached this machine here, the photograph is a little blurry, but it was very clear to us but if you zoom in on the screen and apologies for the reflections, again, this was just taken with my cell phone, you see what appear to be three huge buttons and at the top it said something like have a Charlie Card, which may very well apply to a lot of locals.

所以，我们走近这个机器，这个照片有点模糊，但对于我们来说是清楚地,如果我把它在屏幕上放大，我对这个影像感到抱歉,但是，这是用我的手机拍的,你们可以看到这里上面有三个很大的按钮,写了一些关于Charlie卡片的东西，对本地人来说是相当熟悉的。

哈佛公开课 - 计算机科学课程节选