urea

Meanwhile, the resin of urea and formaldehyde is used for medium-density overlay (MDO), a combination of concrete and plywood, used in concrete moulds.

同时，尿素甲醛的树脂用于制造中密度板（MDO），这是一种混凝土和夹板的组合体，通常用于混凝土模具中。

Nitrogen compounds, like urea, a big component of urine, are transformed over several steps.

含氮化合物如尿的主要组成成分尿素则经过几步被转化。

"Marine animals release small amounts of urea, but the pollution problem is almost entirely human caused, " says Kudela.

库德拉认为海洋动物排泄的尿素很少，污染问题几乎都是人类造成的。