The question below consists of a set of labelled sentences. Out of the four options given, select the most logical order of the sentences to form a coherent paragraph about the role of water in the biosphere and the water cycle: P – On the earth, liquid forms and solid forms (ice/snow) predominate. Q – The water cycle has two distinct branches, the atmospheric branch and the terrestrial branch. R – Water plays a versatile role in the functioning of the biosphere. S – In the atmospheric branch, water exists mainly in gaseous form.

Introduction / Context:
This para-jumble question presents four labelled sentences (P, Q, R, S) and asks you to arrange them into a coherent paragraph. The theme is the role of water in the biosphere and the structure of the water cycle. Para-jumbles test your ability to identify topic sentences, logical progression, and the correct sequence of supporting details.

Given Data / Assumptions:
- Sentences:
- R: Water plays a versatile role in the functioning of the biosphere.
- Q: The water cycle has two distinct branches, the atmospheric branch and the terrestrial branch.
- S: In the atmospheric branch, water exists mainly in gaseous form.
- P: On the earth, liquid forms and solid forms (ice/snow) predominate.
- Options: RSPQ, RQSP, RPSQ, RQPS.
- We assume the paragraph should smoothly introduce the topic, then explain parts of the water cycle, and finally give specific details about forms of water on earth and in the atmosphere.

Concept / Approach:
The first step in para-jumbles is to find the most general sentence which can act as a topic sentence. Here, R is clearly the broadest statement, introducing water and the biosphere. Next, we look for a sentence that naturally follows by narrowing down to a specific aspect of water, in this case, the water cycle in Q. Once the two branches are introduced, it is logical to describe each branch. S talks about the atmospheric branch and P contrasts it with conditions on earth (terrestrial branch), giving the forms in which water predominates.

Step-by-Step Solution:
Step 1: Choose the opening sentence. "Water plays a versatile role in the functioning of the biosphere" (R) clearly introduces the general topic and is ideal as the first sentence.Step 2: After R, a reasonable next step is to mention the water cycle, which is a key way in which water interacts with the biosphere. Sentence Q, "The water cycle has two distinct branches..." naturally narrows the discussion.Step 3: Once Q introduces the atmospheric and terrestrial branches, we can explain one branch in more detail. Sentence S focuses on the atmospheric branch, stating that water exists mainly in gaseous form.Step 4: Sentence P, "On the earth, liquid forms and solid forms (ice/snow) predominate", then describes the situation on earth, which corresponds to the terrestrial branch, and neatly complements S.Step 5: Thus, the best logical order is R – Q – S – P, which is represented by option RQSP.

Verification / Alternative check:
Read the full paragraph in the proposed order: "Water plays a versatile role in the functioning of the biosphere. The water cycle has two distinct branches, the atmospheric branch and the terrestrial branch. In the atmospheric branch, water exists mainly in gaseous form. On the earth, liquid forms and solid forms (ice/snow) predominate." This reads smoothly and moves from general concept to specific descriptions of each branch. Any other order either starts too narrowly or mixes atmospheric and terrestrial details in a confusing way.

Why Other Options Are Wrong:
- RSPQ: Moves from general role to atmospheric detail, then to earth forms, and only later mentions that there are two branches, which breaks logical flow.
- RPSQ: Jumps from general role to terrestrial forms, then back to the existence of branches, which feels disjointed.
- RQPS: Introduces the branches but then places P before S, mixing terrestrial details before clearly explaining the atmospheric branch.

Common Pitfalls:
Students sometimes rely only on the labels P, Q, R, S without reading the actual content carefully, or they decide based on superficial clues like the presence of brackets. The key in para-jumbles is to follow the logical progression: introduction, categorisation, and then detailed explanation of categories. Always check that pronouns or references such as "the atmospheric branch" have been introduced before they are discussed. Here, Q must precede S and P because it defines the branches in the first place.

Final Answer:
The most logical order of the sentences is R – Q – S – P, corresponding to option RQSP.