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寝る， 寐る， ねる
1. to sleep (lying down)
2. to go to bed, to lie in bed
3. to lie down
4. to sleep (with someone, i.e. have intercourse)
5. to lie flat (e.g. of hair)
6. to lie idle (of funds, stock, etc.)
7. to ferment (of soy sauce, miso, etc.)
睡觉（躺下）；上床睡觉，躺在床上；躺下
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
tbd