是when did it started还是when did it start?

是when did it started还是when did it start? When did it start? when did it start? 解释 It's raining .when did it start? -It's raining!When did it start? When did it start?About ______ ago. when did the fire star start it started at 11.40 a.m and ___ When did it start?为什么did用过去式? When did it start?About ______ago.怎么填? when did you start doing it?请翻译 when did you have it When did you know it?