xyst

例句：

1. 1. The doctor prescribed a medicine to treat the patient's condition.
   医生给病人开了一种药来治疗他的病情。
2. 2. The chemical reaction between hydrogen and oxygen produces water as a byproduct.
   氢气和氧气之间的化学反应产生水作为副产品。
3. 3.The factory uses sulfuric acid to process the ore.
   工厂使用硫酸来处理矿石。