harmful metal的用法和樣例：
例句
- Calcium citrate is also used as a water softener because the citrate ions can chelate unwanted metal ions.
檸檬酸鈣也可以用來(lái)作為水柔軟劑，因為檸檬酸離子螯合有害金屬離子。 - The pro and con of using these methods were analyzed, and the application of other possible methods of harmful metals in tobacco was previewed.
作者簡(jiǎn)述了各種方法的優(yōu)缺點(diǎn)，展望了其它有害金屬檢測方法在煙草中的應用。
