Actinium series
[化] 锕系(指89~103号元素)
🧩 词语组成解析
n. 锕\\n[化] 锕Ac
🗣️ 情景例句
It's a good investment.
这是一项好投资。
When can we expect its delivery?
什么时间能发货呢？
This is the best material we have to offer.
这是本公司所供应的最好的原料。