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to open out (of a view, scenery, etc.); to spread out; to become clear (of a road, visibility, etc.); to open up
to improve (of luck, prospects, etc.); to get better
to develop (of a town, civilization, etc.); to become civilized; to modernize; to grow; to advance (of knowledge, ideas, etc.)
to be sensible; to be understanding; to be enlightened
to open (of a new road, railway, etc.); to be opened to traffic
to become populous; to become densely built; to become bustling
「開ける」 has other readings with different meanings.
目の前に広い平野が開けた。
A wide plain spread out before my eyes.
努力を続けていれば、きっと運が開けるよ。
If you keep at it, your luck is sure to improve.
この町は最近かなり開けてきた。
This town has developed quite a bit recently.