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to protect; to guard; to defend
to keep (i.e. a promise); to abide (by the rules); to observe; to obey; to follow
家族を守るために働いているんだ。
I work to protect my family.
約束を守ることが大切だと思う。
I think keeping promises is important.
約束を守ると彼に誓った。
I swore to him that I'd keep my promise.