3 While I walked / was walking to school, it started /
was starting to rain.
4 John arrived / was arriving while my sister made /
was making breakfast.
5 My brother climb / was climbing a tree when he fell /
was falling.
B I didn't meet / wasn't meeting my teacher while we
shopped / were shopping.​

Ответ:

3. was walking, started

4. arrived, was making

5. was climbing, fell

6. didn't meet, were shopping

Объяснение:

3)was walking,it started

4) arrived,was making breakfast

5)was climbing,he fell

6) didn't meeting,were shopping