HSK 7-9
不由自主
bùyóuzìzhǔ(idiom) can't help but; involuntarily
听到音乐她不由自主地起舞。
Tīng dào yīn yuè tā bù yóu zì zhǔ dì qǐ wǔ.
She began to dance involuntarily when she heard the music.
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Appears across levels (7-9) in the HSK 3.0 word list.