Gōng / rén / zhèng / zài / jiǎn / chá / wū / dǐng / lǐ / de / tōng / fēng / guǎn / shì / fǒu / lòu / qì工人正在检查屋顶里的通风管是否漏气。The workers are checking whether the ventilation duct in the roof is leaking.