class 9 had a great time on the school trip一般疑问句和肯否回答
问题描述：
class 9 had a great time on the school trip一般疑问句和肯否回答
答
因为是had，所以用助动词did
一般疑问句：Did class 9 have a great time on the school trip？
此初为问句，所以had还原成have
肯定回答和否定回答很简单，因为已经确定了助动词did
肯定回答：Yes,they did. 否定回答：No,they didn't.
class 9是复数，所以用they
答
did class 9 have a great time on the school trip?
yes, they did/no, they didn't
答
Did class 9 have a great time on the school trip?
Yes,they did.
No,they didn't