Ответы
1) Helen ... (was washing) the dishes when I ... (came) into the kitchen.
2) When we got your message you... had already left our town.
3) Tony ... (was listening) to the latest news while his wife ... (was making) a cup of tea for him.
4) Sam... (was walking) home when he ... ( heard) a cry for help.
5) When Pete ... ( turned off the computer he ... ( realized that he ... (had not saved) his work.
6) Mr Ricks ... (was driving) a car when he ... ( remembered) that he ... (had not taken) his driving licence.
7) Vicky walked/was walking the dog after she had written an essay. оба варианта
8) When l... ( met) Fred he... (was choosing) a present for his friend who ... (had had) a birthday the day before.
9) While Alice ... (was reading) the article she ... ( noticed) that the author ... (did not mention) some historical facts.
10) When Mark ... (was looking) through the instruction one more time he ... (understood) that he ... (had pressed) the wrong button of the gadget.