Ответ:
3. When we moved to our street, a new school would be finished soon.
a) is being built
b) was being built
there. We understood it
Событие (переезд) произошло в прошлом, строительство происходило и продолжалось какое-то время.
c) has been built
d) had been built
Ответ: b) was being built
