<p>When I register for CHM 201, can I pick which class/section to enroll since they all have different time and class size? Also, how come some classes are shorter than the others (#21667 is Monday 1:30 pm - 2:20 pm while 21657 is Monday 1:30 pm - 4:20 pm)?</p>
<p>CHM 201 has three different types of sections, and you need to sign up for one of each. L01, the one-hour 225-person section, is the lecture, and you must sign up for it. B0X, the 3-hour sections, are labs and you have to pick one. C0X, the one-hour 15-person sections, are precepts (or “classes”) and you have to pick one of those as well. Note that, especially for the precepts, you may not get your first choice time and will have to be flexible.</p>
<p>Thank you very much. I totally didn’t know that. So for COS 126, I would have to sign up for L01 and P0X?</p>
<p>Yup, L01 is the lecture and P0X are the precepts.</p>