excretin

例句：

1. 1. The dog was very excited to see the new cat and started to urinate in front of it.
   狗看到新猫很高兴，开始在它面前尿尿。
2. 2. The scientist conducted an experiment to test the excretion rate of the chemical.
   科学家进行了一个实验来测试这种化学物质的排放率。
3. 3. The wastewater treatment plant is responsible for removing the excretion from the city's sewage system.
   污水处理厂负责从城市的污水系统中去除排泄物。