Night whitening agent and the enzyme orientation on the tooth die, the die 20 minutes later wearing a tooth can be removed, with 9 consecutive days.

每晚将美白剂和定向酶放在齿模里，戴着齿模20分钟后即可取下，连续使用9天。

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Bleach is often used as a whitening agent when washing clothes.

VOA: special.2009.10.13

The usual whitening agent in cosmetics of the period, lead acetate, is not.

ECONOMIST: The Romans, too, had sophisticated cosmetics