HSK 6
不禁
bùjīn副
can't help (doing sth); can't refrain from
看到旧照片我不禁笑了。
Kàn dào jiù zhào piān wǒ bù jīn xiào le.
I could not help smiling when I saw the old photo.
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New in the HSK 3.0 word list at level 6.