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
She always reminds him of Grandma. Susan
总是让他想起奶奶。
I beg your pardon.Is this seat taken?
请问这个位子被占了吗？
There are four seasons in the year here--spring, summer, autumn and winter.
这儿一年有四季--春、夏、秋、冬。