1) Some people were playing cards when we (entered/were entering/ had entered).
2) They sent all the letters they (had written/ were writing/ wrote) before.
3) The man came into the room and ( put / had put/ was putting)the suitcase onto
the table.
4) After I (cook/had cooked/was cooking) my breakfast I did the washing up.
5) While the children (did/were doing/ had done) the homework mother was
watching the film.
6) I broke the watches my father (presented/ had present/ was presenting) me.​