Description Copper is an essential trace element.

铜离子测试盒说明铜是一种重要的微量元素。

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Essential trace element is indispensable in maintaining body health.

必需微量元素在维持机体健康方面是不可或缺的。

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Selenium is a trace element essential to human body.

硒是人体必需微量元素。

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Selenium is a trace element essential to human body.

硒是人体必需微量元素。

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