根据你所听到的短文内容回答第12至第15题。

Questions 12 to 15 are based on the passage you have just heard.

youdao

作为对原有内容的补充，课程计划网站编辑整理了诸如视频剪辑、考试真题和练习题等与这三科相关的内容。

To supplement high school AP-prep classes, the Web site compiles material relevant to all three subjects, including video clips, exam questions, and practice problems.

youdao

所以如果你能做这些题,对这些内容足够熟悉保证自己能做好，你就能以正常速度完成考试题，考试结果就不会太差。

So if you can just do the problem solving and get familiar enough with it that you're just good at it, so that you can do it with a reasonable speed, you're going to be fine.

youdao

And as a reminder, hopefully I don't need to remind any of you, but exam 1 is on Wednesday, so rather than our clicker question being on something from last class, which is exam 2 material, let's just make sure everyone remembers some small topic from exam 1 material, which is the idea of angular nodes.

而作为一个提醒--我希望大家都不需要提醒，但是这周三就要进行第一次考试了，因此我们的这个选择题,不是关于上节课内容的，那是第二次考试的内容，这里只是想确认大家都记得,第一次考试所要求的一些小问题，也就是关于角向节点的概念。

麻省理工公开课 - 化学原理课程节选