为了清除空气污染，这个城市加强了对工厂的管理。

Wèile qīngchú kōngqì wūrǎn, zhè gè chéngshì jiāqiáng le duì gōngchǎng de guǎnlǐ.

To eliminate air pollution, this city has strengthened its management of factories.

我们需要定期清除电脑里的无用文件。

Wǒmen xūyào dìngqī qīngchú diànnǎo lǐ de wúyòng wénjiàn.

We need to regularly delete useless files from the computer.

请先清除桌面上的垃圾，再开始工作。

Qǐng xiān qīngchú zhuōmiàn shàng de lājī, zài kāishǐ gōngzuò.

Please clear the trash off the desk before you start working.