past Tense vs past continuous

My brother ... (sing) a song when I knocked the door last night.

• was singing

• singing

• sang

• singed

The baby screamed while I ... (open) the door.

• was opening

• were opening

• opened

• opens

I ... (not, like) milk when I was a baby

the students did not listen when the teacher ...

• explain

• explained

• was explaining

• explaining

She was reading a book when the phone ...

• ring

• rings

• was ringing

• ringing

The cat ... (sleep) when the dog barked.

• sleeps

• was sleeping

• slept

• sleeping

We ... (play) football when it started raining.

• play

• played

• were playing

• playing

He ... (read) a book when the doorbell rang.

• reads

• was reading

• read

• reading

They ... (dance) at the party when the music suddenly stopped.

• danced

• dances

• was dancing

• dancing

She ... (paint) a picture when the phone rang.

• paints

• painted

• was painting

• painting