B-b fraction
[化] 丁烷-丁烯馏分
🧩 词语组成解析
🗣️ 情景例句
My new shoes hurt my feet ...
我的新鞋弄痛了我的脚……
We used to have a lot of fun when we were that age.
当我们是变老时，我们过去常有很多趣事。
I once spend an uncomfortable weekend which I shall never forget at his house.
有一次，我在他家里度周末，过得很不愉快。这事我永远不会忘记。