...A. I am B. I was C. Yes, I was D. No, I wasn't...
When did you have it? 你是什么时候吃的?(关心的是吃的动作发生在何时。)I had it about ten minutes ago. 我大约是十分钟以前吃的。)Used to do something 表示过去常做而现在已经停止了的习惯动作。I used to work fourteen hours a day. 我过去常常一天干十四个小时。I ate it at 6:45。我在六...