copper-gold alloy的用法和樣例：
例句
- The etching liquid etches the gold or gold alloy layer existing between the columns evenly.
該蝕刻液均勻蝕刻柱之間存在的金或金合金層。 - The main problems in determination of gold by the back titration for the excessive FeSO4 with potassium bichromate were discussed and experimented.
對重鉻酸鉀滴定過量硫酸亞鐵返滴定法測定金合金中金的主要問題做了探討和實驗。
