1. I saw/ was seeing the accident when I was waiting for the taxi.

2. What were you doing/ did you do when I phoned? (Ê cậu đang làm gì trong lúc tớ gọi cậu vậy?)

3. They didn't visit/ weren't visiting their friends last summer holiday. ( chú ý dấu hiệu last summer holiday nha)

4. It rained/ was raining heavily last July. (dấu hiệu: last July)

5. While people were talking to each other, he read/ was reading his book. ( dấu hiệu quá khứ tiếp diễn là sự xuất hiện hiện của bạn nhỏ "While" nhoaa)

6. Chris was eating/ ate pizza every weekend last month.

7. While we were running/ run in the park, Mary fell over. 

8. Did you find/ Were you finding your keys yesterday? ( Dấu hiệu: Yesterday)

9. Who was she dancing/ did she dance with at the party last night? ( Dấu hiệu: Last night)

10. They were watching/ watched football on TV all day. ( dấu hiệu: all day).

Well well well, Lord Potato chúc bạn học tốt nhoaaa