So that explains probably most of the confusion here and you just want to be careful when you're reading the problems that that's what you read correctly. I think 4 everyone would now get the clicker question correct.

这可能解释了大部分人的混淆之处,你们读题目的时候一定要仔细,我相信现在每个人都能回答正确了,第三激发态，n等于。

麻省理工公开课 - 化学原理课程节选

Absolutely. You just have to be careful and you know, constantly be looking everywhere.

肯定的啦。你不得不小心一点，并且不断地观察周围的情况。

喜欢自行车 - SpeakingMax英语口语达人

I just go through these equations, 3 but be careful to Z equals three.

我只检查这些方程式，但是注意了，Z等于。

麻省理工公开课 - 固态化学导论课程节选

And if you've typed in l when you should've 1 typed a 1, or a 1 when you should've typed an l, you're likely to miss it. If you've made a mistake with upper and lower case. Things like that. So just be very careful looking at that.

如果你本来想打，1，的时候,却输成了，l，或者打，l，的时候输成了，你很可能注意不到这个错误,如果你把大小写弄混了也是一样,要注意这个错误。

麻省理工公开课 - 计算机科学及编程导论课程节选