Inside
Within
The inside radical and the inside kanji are exactly the same, yay. But is the radical inside the kanji here, or is the kanji inside the radical? I don't know, it's inside-ception.
ない
うち
None
If you need to get inside something, the quickest way is to use a knife (ない). With a knife, you can cut something open and see what's inside it and within it.
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