| 污染HSK 4 | wū rǎn | pollution; contamination; Classifiers: 个 | |
| 感染HSK 6 | gǎn rǎn | infection; to infect; to influence | |
| 传染病HSK 6 | chuán rǎn bìng | infectious disease; contagious disease; pestilence | |
| 传染HSK 5 | chuán rǎn | to infect; contagious | |
| 传染性 | chuán rǎn xìng | infectious; epidemic |
| 1 | Her grin was infectious. | |
| 2 | Her smiling face infected my mood. | |
| 3 | Industrialization will increase the degree of pollution. | |
| 4 | The air pollution in the city is getting worse and worse. | |
| 5 | Environmental pollution has become a global issue. |