S1:	Forecasting the weather has always been a difficult business.
P :	During a period of drought, streams and rivers dried up, the cattle died from thirst and were ruined.
Q :	Many different things affect the weather and we have to study them carefully to make accurate forecast.
R :	Ancient Egyptians had no need of weather in the Nile Valley hardly ever changes.
S :	In early times, when there were no instruments, such as thermometer or the barometer, man looked for tell-tale signs in the sky.
S6:	He made his forecasts by watching flights of the birds or the way smoke rose from fire.

The Proper sequence should be: