The parts P, Q, R, and S of the following sentence have been jumbled. Choose the order that forms a coherent sentence: S: the world's fastest computers initially conceived Q: for military purpose R: are finding various new uses P: as environmental tools.

Introduction / Context:
This sentence arrangement problem is about the changing uses of supercomputers. The statement explains that very fast computers, originally built for military purposes, are now used as environmental tools. The challenge is to order the fragments so that the descriptive and main clauses appear in their natural positions.

Given Data / Assumptions:
The fragments are:
- S: the world's fastest computers initially conceived
- Q: for military purpose
- R: are finding various new uses
- P: as environmental tools
One of these fragments will start the sentence, and all must be used.

Concept / Approach:
The logical beginning is S, which introduces the subject "the world's fastest computers initially conceived". The phrase Q "for military purpose" completes the idea of initial design. After that, the main verb phrase R "are finding various new uses" tells us what is happening now, and P "as environmental tools" describes one of those uses. The natural progression is subject and original purpose, followed by present uses.

Step-by-Step Solution:
Step 1: Begin with S: "The world's fastest computers initially conceived". This sets the subject and hints at their original design goal. Step 2: Add Q: "for military purpose", completing the thought "initially conceived for military purpose". Step 3: Continue with R: "are finding various new uses". This introduces the contrast between original intention and current applications. Step 4: Conclude with P: "as environmental tools", specifying the kind of new uses that are being found. Step 5: The full sentence is "The world's fastest computers, initially conceived for military purpose, are finding various new uses as environmental tools."

Verification / Alternative check:
Now map this sequence to the options. S Q R P appears as option A. If we tried option C, R P S Q, we would start with "are finding various new uses as environmental tools the world's fastest computers initially conceived for military purpose", which is extremely awkward and does not follow normal English word order. Starting with Q or P also fails because they are dependent phrases lacking subject and verb.

Why Other Options Are Wrong:
- "P Q R S": begins with "as environmental tools", which cannot serve as the main subject and makes the sentence fragmentary.
- "R P S Q": starts with the verb phrase "are finding various new uses" without a clear subject, and then strings together the remaining phrases in an unnatural way.
- "Q P S R": moves the purpose phrase to the front, causing confusion about which computers are being discussed until much later.

Common Pitfalls:
In para jumbles with technical or scientific content, candidates sometimes focus too much on individual words like "military" or "environmental" and forget to look for the subject verb core. Always look for the fragment that provides a clear noun phrase subject plus some descriptive material. Then, ensure that verb phrases follow in a way that maintains logical time order: original purpose before current use in this case.

Final Answer:
The correct sequence is S Q R P, producing a clear and meaningful sentence about how supercomputers are being repurposed as environmental tools.