There is a scratch panel - just like a lottery ticket with number on the drug - each drug has a different number.

VOA: standard.2010.06.07

Thus far and in Scratch will pretty much focus on the idea of correctness: Does your code work as we asked it to and as you intended it to?

至此，人们大都是把注意力集中于正确性,观点上：你的代码是不是根据你的意愿,并按照你的要求来执行呢？

哈佛公开课 - 计算机科学课程节选

So first thing we should do is scratch our heads and see what's going on here. Alright, let's look at it. What's happening here?

所以我们要做的第一件事,就是抓抓脑袋看看发生了什么,好了，让我们来看看，这儿发生了什么呢？

麻省理工公开课 - 计算机科学及编程导论课程节选

So with problems at zero, ; which will be posted in two forms; PDF PDF for standard and PDF for hacker on cs50.net tonight, you will have the choice of implementing pretty much any scratch projects you can think of, and which subject to very few constraints.

对于问题集，我们提供了;,标准PDF以及可编程,今晚它们都会被放在CS50，net上，你可以选择任何,你想到的项目，范围不限。

哈佛公开课 - 计算机科学课程节选