单选题 I suppose the party ended in a friendly atmosphere, isn't it?
A. don't I B. do I C. did it D. didn't it

【正确答案】 D
【答案解析】[解析] 本句考察反意问句的用法：陈述句谓语用肯定形式，疑问句谓语动词要用否定形式，因此选项B和C不对；陈述句强调的谓语动词是ended，所以反意问句应为didn't it，选项D是答案。