Para-jumble (forecasting the weather): Reorder the sentences to explain why weather prediction is difficult and how early observers made forecasts from natural signs. S1 = "Forecasting the weather has always been a difficult business." S6 = "He made his forecasts by watching flights of the birds or the way smoke rose from fire." Between S1 and S6, place the four fragments in a logically developing order: 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." Choose the correct sequence of P–Q–R–S that completes the paragraph.

Given data

• S1: Weather forecasting is difficult.
• Q: Many interacting factors affect weather; careful study is needed for accuracy.
• P: Illustration of the stakes (drought and losses) when weather turns adverse.
• R: In the Nile Valley, weather changes little; the ancient Egyptians had less need to forecast.
• S: In early times without instruments, people relied on sky signs.
• S6: Concrete examples of natural signs (birds' flight, smoke behavior).

Concept / Approach
Start with the underlying reason for difficulty (Q), then motivate urgency with consequences (P), add a contrasting historical context where forecasting mattered less (R), and finally present the primitive method used before instruments (S), which leads seamlessly into the examples in S6.

Step-by-step ordering
S1 + Q → Complexity explains why forecasting is hard.… + P → High-impact consequences underscore importance.… + R → Contrast: one region with little change had less need.… + S → Without tools, observers used sky signs, setting up S6's examples.

Why other orders fail
PRQS begins with consequences before giving the reason for difficulty; QRPS prematurely shifts to ancient Egypt before establishing stakes; SPQR jumps to methods before explaining complexity or urgency.

Final Answer
QPRS