Past Perfect vs Past Perfect Continuous

We  ...   the contract before the meeting ended.

His English was perfect. He  ...   it since he started school.

She didn't go to work. She  ...   a cold.

I arrived on Sunday. I  ...   at home for two days.

As soon as Betty ... the door, the burglar alarm went off.

When she went out to play, she ...  her homework.

We ...  there since 1980, you know.

I had to leave because I ...  to meet Kathy in front of the theater.

We didn't know what to do because we ...  to the teacher.

I was sure that I ...  him before.

We ...  the play when the lights went off.

She ate  all of the food that we ....