请问为什么是didn't imagine,而不是haven't imagine?

请问为什么是didn't imagine,而不是haven't imagine? he must have finished his homework last night,didn't he?为什么是didn't but i don't think you can smoke here.I didn't know this is a...为什么是didn't i didn't know you had called the police before l came here为什么是didn't 而不是don't You can't imagine that rats eat 40 to 50 times their weight.为什么是 their weight 英语翻译是I didn't spoke English.还是I didn't speak English.为什么是用动词原形？仔细一点 英语-为什么是he didn't get up yesterday而不是he wasn't get up yesterday 为什么是“She didn't think she was clever.”而不是“ she think she wasn't clever”? He must have been asleep at that time,(wasn't) he?为什么是用 wasn't 而不是 didn't You can't imagine _____ when they received these ice christmas presents请问空格里面填什么：A,how they were excited.B,how excited they were.选A还是B那为什么是A或者为什么是B而不是A解释谢谢.HOW哪个句子的宾语从句 i didn't know they would go to Japan 为什么是they would You must have met her yesterday的反意疑问句为什么是didn't it i didn't want to (take part in ) their argument为什么是take part in She didnt think___she did wrong that day. 为什么是what而不是 that? 分析句子结构She didn't have it in her to cheat.为什么是her为什么是to+do? Don't Imagine This They must have done their homework yesterday,___?为什么是didn't they?我觉得应该是haven't they啊? 请问什么是t-test