Array ( [0] => Array ( [title] => L4A1 [link] => https://www.youtube.com/embed/6B9OgPgf1n4 ) [1] => Array ( [title] => L4A2 [link] => https://www.youtube.com/embed/pYMxR9piONo ) [2] => Array ( [title] => L4B1 [link] => https://www.youtube.com/embed/DMfSov8tMXY ) [3] => Array ( [title] => L4B2 [link] => https://www.youtube.com/embed/uej_ndW2e5w ) [4] => Array ( [title] => L4C1 [link] => https://www.youtube.com/embed/kF0yoxT53vE ) [5] => Array ( [title] => L4C2 [link] => https://www.youtube.com/embed/-xfx4OpH4lc ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第4R講 葛逖爾難題(續)