1) was she drinking tea at 2 o’clock yesterday?
she was not (wasn’t) drinking tea at 2 o’clock.
2) was my sister playing computer games at 5 o’clock yesterday?
my sister was not (wasn’t) playing computer games at 5 o’clock yesterday.
3) were they walking their dog at 6 o’clock yesterday?
they were not (weren’t) walking their dog at 6 o’clock yesterday.
1) was she drinking tea at 2 o’clock yesterday?
she was not (wasn’t) drinking tea at 2 o’clock.
2) was my sister playing computer games at 5 o’clock yesterday?
my sister was not (wasn’t) playing computer games at 5 o’clock yesterday.
3) were they walking their dog at 6 o’clock yesterday?
they were not (weren’t) walking their dog at 6 o’clock yesterday.