选修 (xuǎn xiū): elective course

I major in computer science, but this semester I took an elective in psychology because I'm very interested in human behavior.

The school stipulates that undergraduates must take at least two humanities electives in order to graduate.

She originally wanted to take French as an elective, but the class schedule conflicted with her major courses, so she had to switch to Spanish.

This elective course requires a book report every week; although there is a lot of homework, I can learn a lot of new knowledge.

If you are interested in photography, you can take this elective; the teacher will teach you how to take professional photos.