In order to switch which subject you're learning, click on the Subjects drop-down at the top left of your page.
Hover over the subject or class, which will show up as underlined, and click on the link.
This will bring you to a topics page where you can select either a topic directly, or in some cases select a class and then a topic.
Last updated September 29, 2017
Images updated September 29, 2017