Butene
n. [化]丁烯
🗣️ 情景例句
At the Bronx High School of Science.
在Bronx区的理科中学读书。
Do you have an umbrella?
你有雨伞吗？
Ethanol is more effective at a concentration of 50-70 percent;
乙醇的浓度为50％至70％时比较有效，