关键词：
参考技术A Didn't they eat lunch under the trees?难道他们不是在树下吃午餐吗？Yes, they did.
No, they didn't. 参考技术B They ate their lunch under the trees.
变否定句：
They didn’t eat their lunch under the trees.
疑问句:
Did they eat their lunch under the trees?
肯定回答：
Yes, they did.
否定回答：
No, they didn’t. 参考技术C 结构2：名词或代词(主格) + doing
1)My mother cooking in the kitchen, I was doing my homework in my room. （表伴随）我妈妈正在厨房做饭，我在房间里做作业。 参考技术D The ate their lunch under the trees变否定句疑问句肯定和否定回答？
Change the negative question to affirmative and negative?