The plants 艹 are made by the sun 日 to be large 大 [= as long shadows] at sunset. - The very similar radical stands for sunrise. This seems bizarre, but can be argued based on the characters for morning 朝 in comparison to evening 暮.
Tip: Go to the radicals that are contained in this character and learn all the characters with this radical systematically!
Vocabulary
薄膜
bó mó
membrane; film
4301
笛膜
dí mó
membrane which covers a hole in a flute and produces a buzzing tone
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