排烟

gōng chǎng de yān cōng xiàng gāo kōng pái yān

工厂的烟囱向高空排烟。

Factories chimneys discharge smoke into the atmosphere.

xū yào duì pái yān xì tǒng jìn xíng yán jiū hé cè shì

需要对排烟系统进行研究和测试。

Research and testing of smoke venting systems needs to be undertaken.