Past perfect vs past simple

When I arrived late to the school, the exam....

• had already started

• have already satarted

• has already started

I .... Verónica to repeat the question because I hadn't heard it the first time.

• have asked

• had asked

• asked

He didn't know the answers because he .....

• didn't study hard

• hadn't studied hard

• hasn't studied hard

She .... delighted because she had won the race.

• had been

• is

• was

I wanted to ask Paloma a question but she ....

• has gone for lunch

• had gone for lunch

• went for lunch

I ..... how to do the essay because I hadn't read the instructions properly.

• don't know

• hadn't known

• didn't know

When the phone rang, I ....

• have just locked the door.

• locked the door

• had just locked the door.

It had been a cold, dark day and then the sun ...

• has come out

• have come out

• had come out

• came out

My parents ...... when I arrived home

• have left

• had left

• left

By 9 am, I .....

• 'd sent three emails

• 've sent three emails

• sent three emails