1.I want to eat some food. I have a sore throat. (but)
⇒ I want to eat some food, but I have a sore throat.
2. The Japanese eat healthily. They live for a long time. (so)
⇒The Japanese eat healthily, so they live for a long time.
3. I feel tired. I feel weak. (and)
⇒I feel tired, and I feel weak.
4.You can go and see the doctor. You can go to bed now and rest. (or)
⇒You can go and see the doctor or you can go to bed now and rest.