Sure! Here are the sentences completed with the past simple or past progressive forms of the verbs provided:
1: When I was helping in the kitchen Mary came. 2: While she was cooking the soup the children were playing. 3: While they were playing cards the baby was sleeping. 4: When I was working in the garden my uncle called. 5: Carol was watching TV while Bob and Peter were playing football. 6: When she was washing her hair the baby began to cry. 7: A strong wind was blowing when the plane landed. 8: When she was playing tennis it began to rain. 9: When I was watching TV the lights went out. 10: While he was playing the piano she was listening to him. 11: While she was tidying up her room he was washing his car. 12: The boys were helping in the garden while she was watering the flowers. 13: He met Mary when he was walking through the park. 14: We were playing computer games while she was reading a book.
Feel free to ask if you need further assistance!