C
Jill was ironing while Peter was doing washing-up.
Susan was having a shower when the doorbell rang.
David got into his car, started the engine and drove away.
D
used to
used to
didn't use to
used to
E
since
was watching
has tried
was going to call
has read
when
wanted
used to
D
started - had left
fa: had left
had bought - went
fa: had bought
passed - had studied
fa: had studied
had taken - went
fa: had taken