On this week's 'Idol School', the students put on performances of the hit tracks by Lovelyz, TWICE, and Red Velvet.
All 3 groups put on a wonderful show, so we want to know, out of the 3 groups, which one do you like the best?
Watch the performances and vote for your favorite in the poll below!
SEE ALSO: Watch 'Music Bank' Live!
Lovelyz ''Ah-Choo'' by Yoon Ji Woo, Cho Young Joo, Lee Si Ahn, Cho Yoo Bin, Noh Ji Sun, Snow Baby, and Cho Se Rim
TWICE ''Cheer Up'' by Shin Si Ah, Lee Na Kyung, Lee Chae Young, Song Ha Young, Kim Eun Seo, Tasha, Bin Ha Neul, and Kim Joo Hyun