B-b fraction
[化] 丁烷-丁烯馏分
🧩 词语组成解析
🗣️ 情景例句
I'm working on-it.
我正在做这项工作。
Who is he?
他是谁？
He had often dreamed of retiring in England and had planned to settle down in the country.
过去他常幻想退休后到英国，并计划在乡间安顿下来。