He said states would have until 2014 to opt out of the program, calling it the "fairest way to go."

VOA: standard.2009.10.26

If you decide to opt in by a pass fail, I just need to sign your white study card or if you wanna decide before the 5th Monday, just grab the pink slip and I can sign that and you can turn that in at any point and I'm happy to chat during break today or after class if you have any questions or concerns.

如果你上我们的课程只是要一个分数，那么我只需要在你的白卡片上签个名就可以了,或者说，如果在第五周的周一前还没考虑好，把你的解聘书拿来，只要我签个字,任何时候你都开以离开我的教室,当然，如果你有任何问题和疑虑,我也很高心和大家做课下交流。

哈佛公开课 - 计算机科学课程节选