有效水分 useful water capacity: 有效庫(kù)容distill useful solvents from waste water: 從廢水中蒸餾出有用的溶劑be useful: 有用場(chǎng)be useful for: 對(duì)…有作用例如be useful to: 對(duì)有益; 對(duì)…有用下載手機(jī)詞典可隨時(shí)隨地查詞查翻譯