Объяснение:

1) When I came home yesterday my mother was cooking dinner and my father was working on the computer. 2) We were choosing the flowers when we saw Nick. He was speaking to somebody near the metro. 3) Witty was writing a report from five to eight yesterday. 4) While Maria was dusting the furniture her brother was vacuuming the carpets. 5) First Martin turned off the light and then he locked the door. 6) When the parents returned home, the children were sleeping. 7) It was getting dark when they left the restaurant. 8) What were you doing when I phoned you yesterday? 9) Where was Mike riding when you met him yesterday afternoon? - He was riding to the post-office. 10) When did your sister finish reading this book? - She was reading it all day yesterday and finished reading late in the evening.