l. A serious road accident happened. There was a traffic chaos yesterday. (CAUSED) 

 The traffic chaos yesterday caused a serious road accident.

2. I had to get the mop. I spilled my juice. (SINCE)  

  I had to get the mop since I spilled my juice.

3. He walked slowly. He has a bad leg. (BECAUSE OF)

  He walked slowly because of his bad leg.

4. A peacock will spread his feathers, he will attract a female. (SO) 

  A peacock will spread his feathers so he will attract a female.

5. The cyclone has come. Many thousands of deaths. (RESULTED IN)  

  The cyclone has come, which resulted in many thousands of deaths.

6. Don't eat too much sugar. It creates health problems. (LEAD TO)

  Eating too much sugar can lead to health problems.

7. The weather was bad. That's why our departure delayed (BECAUSE OF) 

  Our departure delayed because of the bad weather.

8. There was damage to our property because of the fire. (RESULTED IN)  

  The fire resulted in the damage to our property.

9. They haven't reply our invitation so far. I think they are not coming. (SINCE)  

  I think they are not coming since they haven't reply our invitation so far.

10. The road condition is poor. There has been several accidents. (CAUSED)  

  The poor road condition has caused several accidents.