Ответ:

1. i didn't buy the computer because it was too expensive.

2. we weren't quiet enough in our exam so teacher gave us extra homework.

3.we were too hot so we opened the window.

4. i didn't go to the night club because i wasn't old enough to get in.

5. when we went cycling, we didn't wait for Simon because he was too slow.

6. My wardrobe isn't big enough for all my clothes so a lot of them are on the floor.