New words：

pollution [pə'lu:ʃən] n. 污染；污染物

Sample Sentences：

We have freed the lake from pollution.
The new law will reduce pollution of the rivers.
We are sad about the pollution of our beaches with oil.
Many beautiful fish are fast disappearing because of the severe pollution.

severe [si'viə] adj. 极为恶劣的；十分严重的；严厉的

标签: none