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:

S1:Forecasting the weather has always been a difficult business.P :Dur

1.	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:
A.	QRPS
B.	PRQS
C.	QPRS
D.	SPQR
Answer» D. SPQR