Objective To study the biological limit of urine trans, trans-muconic acid(t, t-MA)for occupational exposure to benzene.

目的研究职业性苯暴露反-反式粘糠酸（t，t-MA）生物接触限值。

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"Ma 'am," the officer replies, you weren't speeding, but you should know that driving slower than the speed limit can also be a danger to other drivers.

“女士，”警官回答说，“你是没有超速，但你必须知道，有时候没有超速也会对其他的司机形成危险。”

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"Ma 'am," the officer replies, you weren't speeding, but you should know that driving slower than the speed limit can also be a danger to other drivers.

“女士，”警官回答说，“你是没有超速，但你必须知道，有时候没有超速也会对其他的司机形成危险。”

youdao