Dưới đây là những câu hoàn chỉnh dựa trên các ý của bạn:

1. We couldn't eat the food because it was very hot.
2. A taxi would have been best, but I didn't have much money.
3. Sarah can't take a day off since she's very busy.
4. A picnic would be nice, but it's wet outside.
5. Nobody could move the piano as it was very heavy.
6. I don't wear this coat in winter because it isn't warm enough.
7. All my guests will need chairs, but I haven't got very many.
8. I can’t explain the situation because it’s complicated.
9. Three people can't sit on this sofa since it isn't wide enough.
10. I couldn't carry the equipment because I had such a lot.
11. We couldn't climb over the wall because it was very high.
12. Natasha wants to be a professional musician because she's very good.
13. We shouldn't swim in this river since the water isn't clean.
14. You can't see some things without a microscope because they are very small.
15. He didn’t get a job because he wasn’t experienced.