When or while?

Warning: Answers follow!

Combine the two sentences into one sentence by creating an adverbial clause with when or while.  (answers are at the bottom)

1.  I was making dinner.   My sister was watching television.
2. We were watching the movie called "King Kong".   A friend came over.
3. We were watching the movie.  We were laughing about its unlikely plot.
4. The the movie ended. We turned off the TV.
5. I was talking on the phone.  My friend was reading magazines.
6.   My friend stood up to leave.  It was midnight.
7. He touched the door knob.    We heard a thud on the roof. 
8. He looked at me. I said, "King Kong?"
9. He opened the front door.   We saw nothing but leaves and branches.

Answer:

 - While I was making dinner, my sister was watching television.

- We were watching the movie called "King Kong" when a friend came over.

- While we were watching the movie, we were laughing about its unlikely plot .

- When the movie ended, we turned off the TV.

- While I was talking on the phone, my friend was reading magazines.

- My friend stood up to leave when it was midnight.

- When he touched the doorknob, we heard a thud on the roof.

- When he looked at me, I said, "King Kong?"

- We saw nothing but leaves and branches when he opened the front door.