clean district的用法和樣例：
例句
- Fumigation of clean areas may be useful for reducing microbiological contamination in inaccessible places.
對潔凈區內難以進入的角落進行熏蒸是減少微生物污染的有用的方法。 - The typical single door lyophilizer opens in the clean area only, and contamination between loads would be minimal.
在單門的箱體上，門只在潔凈區打開，裝載過程中的污染最小。
