Y-
[字首]表过去分词之义
🗣️ 情景例句
He is working on a book about the Vietnam War.
他正在写一本关于越战的书。
What were you doing at about 4 o'clock yesterday afternoon?
你昨天下午在大约4点钟正在做什么？
Yes, I do. But it's only a small one.
是的，有，但是很小。