Write what you had done yesterday:
a) by the time your parent(s) came back home
b) by the time supper was ready
c) by 6 p.m.
d) by the time you came back from school
e) by bedtime
a) I had done my homework by the time my parents came back home.
b) I had checked my mail by the time supper was ready.
c) I had finished reading another book by 6 pm.
d) I had cleaned up the room by the time you came back from school.
e) I'd finished playing computer games by bedtime.
( = listening to music by...; = watching TV by...)
Объяснение: had + V3+ by - к какому-то времени; до какого-либо времени что-то было уже сделано.
2 our
3their
4 our