According to the school rules, the students mustn't get their ears pierced.

根据学校的规定，学生们绝对不能穿耳洞。

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Young girls are often first exposed to nickel when they get their ears pierced, and therefore are more likely to develop a sensitivity to the metal that can cause allergic reactions later on.

当年轻的女性穿耳洞的时候，她们第一次接触到镍金属，因此他们很可能对产生过敏反应的镍金属形成过敏。

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