Usninic acid
[化] 地衣酸
🧩 词语组成解析
🗣️ 情景例句
Philip had to go back to the hospital. Philip
必须要回医院。
We'd like to clear up some points connected with the technical part of the contract.
我们希望搞清楚有关合同中技术方面的几个问题。
If I work in the garden, I have to sit down and rest every five minutes.
如果我在花园里干活，每5分钟就得坐下来休息。