Question

What … at 9 o’clock last night?
a. have you been doing
b. have you done
c. were you doing

Answer 1

Ответ:

What … at 9 o’clock last night?

c. were you doing

Объяснение:

Используем Past Continuous т.к. в предложение есть точный указатель времени (в 9 часов) в прошлом (last night-вчера вечером)