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to jump in; to leap in; to plunge into; to dive
to burst in; to barge in
暑かったのでプールに飛び込んだ。
It was hot so I jumped into the pool.
彼は救助のために川に飛び込んでいる。
He jumped into the river to rescue someone.
店に飛び込んで雨宿りをさせてもらった。
I rushed into a store and got to take shelter from the rain.