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The Shia sect (the twelver branch),which to this date has widely mixed with the Iranians national identity, has taken an important place since the Safavids’ time.
I wouldn't call 'has taken' wrong, but ' has held ' is much more natural and idiomatic.. with the Iranians' national identity with the Iranian national identity I don't undersatnd what it means when 'a sect mixes with a national identity'. Can you say it another way?
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