_:n4da4b8fda0684ac6b00d79639ebe8001xb0
<http://schema.org/url>
<https://zh-tw.coursera.org/instructor/sharon-morsink>
<https://zh-tw.coursera.org/lecture/black-holes-astro-101/04-01-introduction-sizing-up-black-holes-r1jZ7>