Valerolactam
戊内酰胺
🗣️ 情景例句
You can listen to BBC or VOA news if you want to improve your listening.
如果你想提高听力，你可以听英国广播电台或美国之音的新闻节目。
How many sisters and brothers do you have?
你有几个姊妹和兄弟？
People often ask me whether I like being a twin.
人们常常问我是不是喜欢双胞胎。