arc line的用法和樣例：
例句
- Normally, the measured spectral line for the superheated iron atoms would show up as a symmetrical peak.
通常，所測得的超高溫鐵原子光譜線會顯示出一個均勻的尖頂。 - After a little argon was mixed, the breakdown voltage of discharge obviously decreased.The spectral line intensities of nitrogen molecules and nitrogen atoms increased.
在大氣中加入少量氬氣后，擊穿電壓明顯降低，在相同電壓條件下，氮分子光譜線和氮原子光譜線強度都增強。
