1. They couldn't help you. They were not here
-> They were not here so they couldn't help you
-> They couldn't help you because they were not here
2. I can't go out. It's raining
-> It's raining so l can't go out
-> I can't go out because it's raining
3. We haven't got any food. We are going shopping
-> We haven't got any food so we are going shopping
-> We are going shopping because we haven't got any food
4. There was fog. Their flight was delayed
-> There was fog so their flights was delayed
->Their flights was delayed because there was fog
5. The film was boring. We decided to go home
-> We decided to go home because the film was boring
-> The film was boring so we decided to go home
6. I couldn't do this exercise. I asked Tom for help
-> I couldn't do this exercise so I asked Tom for help
-> I asked Tom for help because I couldn't do this exercise