Pentoxide
n. [化]五氧化物
🗣️ 情景例句
I don't know. The baby-sitter says she has a stomachache,
我不知道。临时保姆说她肚子疼.
I still have some questions concerning our contract.
就合同方面我还有些问题要问。
Do you mind if I smoke?
我吸烟你介意吗？