1.  Alice saw/ was seeing the accident when she was catching the bus.

2.  What were you doing/ did you do when I called?

3.  I didn’t visit/ weren’t visiting my friends last summer holiday.

4.  It rained/ was raining heavily last July.

5.  While people were talking to each other, he read/ was reading his book.

6.  My sister was eating/ ate hamburgers every weekend last month.

1. saw                       
2. were you doing
3. didn’t visit
4. rained
5. was reading
6. ate
 

1.  A

2.  A

3.  A

4.  A

5.  B

6.  B