Para-jumble (sentence arrangement): Arrange P–Q–R–S to complete the earth science note about deep oceans, flat beds, and mid-ocean ridges. S1 = "We now know that the oceans are very deep." S = "On average, the bottom is 2.5 miles to 3.5 miles down." Q = "Much of it is fairly flat." R = "However, there are great mountain ranges as well." P = "For example, the Indian Ocean has a range called the Indian Ridge." S6 = "This reaches from India to the Antarctic." Between S1 and S6, place P–Q–R–S in a logically developing geographic order. Choose the correct sequence of P–Q–R–S that completes the paragraph.

Given data

• S1 introduces ocean depth.
• S quantifies the average depth (2.5–3.5 miles).
• Q adds that much of the seabed is flat.
• R contrasts with underwater mountain ranges.
• P gives a specific example: the Indian Ridge (leading into S6).

Concept/Approach
Describe global average → predominant feature (flatness) → contrast (ranges) → named example → concluding extent (S6).

Step-by-step reasoning
After S1, S provides depth numbers to anchor the claim. Q logically follows to characterize the average seafloor. R introduces the contrasting feature of mountains. P supplies the concrete instance (Indian Ridge), which matches S6's geographic span.

Verification/Alternative
Ending with a named ridge allows S6 to state its reach from India to the Antarctic naturally.

Common pitfalls
Placing P too early mentions a ridge before establishing flat vs. mountainous context.

Final Answer
SQPR