Array ( [0] => Array ( [title] => L20A [link] => https://www.youtube.com/embed/0_B57ZwEr8Q ) [1] => Array ( [title] => L20B [link] => https://www.youtube.com/embed/TwKiLWEKiCs ) )
Title
第1節
第2節
Syllabus
L20AB Solving Difference Equations