K-해저터널 기술, 7km 바다 밑에서 정확히 만난 비결은? (신원상 박사)

Picked video by video from 안될과학 Unrealscience (mixed channel): title plainly names a teaching subject. Channel transcript sample: One sample is a genuine (if chatty) science experiment explainer, while the others are sponsored content or talk-show format without verifiable teaching transcripts, consistent with the channel's mixed pick status.