「かぎは錠前に差し込んである」と、彼は付け加えた。
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"The key," he added, "is in the lock."
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差し込む， 差込む， 差しこむ， さしこむ
1. to insert, to put in, to thrust in, to plug in
2. to have a griping pain
3. to flow in, to shine in
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付け加える， つけ加える， 付加える， 付けくわえる， 附加える， 附け加える， つけくわえる
1. to add (one thing to another), to add (a few more words, an explanation, etc.)
添加(某物到另一物)，补充(几句话、解释等)
に
1. at (place, time), in, on, during
2. to (direction, state), toward, into
3. for (purpose)
4. because of (reason), for, with
5. by, from
6. as (i.e. in the role of)
7. per, in, for, a (e.g. "once a month")
8. and, in addition to
9. if, although
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