The challenge is for the work you are going to be doing at the class time we are doing to spend together.

这一挑战是针对,我们要一起在课上,完成的任务提出的。

麻省理工公开课 - 媒体、教育、市场课程节选

So my challenge to you, and I know Professor Guttag can do this, my challenge to you is, a year from now, come back and look at code you wrote here.

因此我这里有个具有挑战性的任务，我知道Guttag也可能会说这个任务，我的这个任务就是，一年以后，回头来看,你之前写过的代码。

麻省理工公开课 - 计算机科学及编程导论课程节选