yangliwei spent about twenty-one hours in space.改成否定句疑问句回答
问题描述：
yangliwei spent about twenty-one hours in space.改成否定句疑问句回答
答
否定：
Yangliwei ddn't spend about twenty-one hoursin space.
疑问：
Did yangliwei spend about twenty-one hoursin space?
Yes, he did.
或No,he didn't.