VOA慢速英语:Next Step After Carbon: Knowing Your Nitrogen Footprint

词汇讲解：

1. footprint n. 脚印，足迹
例句：He squatted down beside the footprints and examined them closely.

2. measure v. 测量，计量
例句：We measured the distance.
我们测量了距离。

3. fertilizer n. 化肥，肥料
例句：Get some more fertilizer for the garden.
给花园再多施些肥料。

4. depletion n. 消耗，用尽
例句：Only when environmental deterioration or resource depletion translates into economic decline do we seem to notice the problem. 
只有当环境恶化或资源的枯竭导致经济衰退时，我们似乎才注意到这个问题。

5. recommend vt. 建议，劝告
例句：will not recommend you for accelerated promotion at this point. 
 目前，我不会建议对你提前晋升。

6. reduce vt. 缩减，减少，降低
例句：He won't reduce the rent of our house.
他不肯减少我们住房的租金。

7. fraction n. 小部分，一点儿
例句：The cost is only a fraction of his salary.
那项费用不过是他薪水的一小部分。

8. excrete vt. 排泄，排除，分泌
例句：The function of the kidneys is to excrete wastes from the body.
肾的功能是排泄人体里的废物。

9. decrease v. 减小，减少
例句：The population began to decrease.
人口开始减少。