The parts P, Q, R, and S of the following sentence have been jumbled. Choose the order that forms a coherent sentence: We can think of P: often confused in the public minds R: two factors Q: which suggest the need for S: an international language.

Introduction / Context:
This item is about reordering a sentence that discusses reasons for adopting an international language. It tests your sensitivity to logical flow and the usual placement of noun phrases and relative clauses. The opening "We can think of" must be followed by a clear object, after which descriptive information and a relative clause are attached.

Given Data / Assumptions:
The pieces are:
- P: often confused in the public minds
- Q: which suggest the need for
- R: two factors
- S: an international language
The sentence starts with "We can think of".

Concept / Approach:
After the phrase "We can think of", English normally expects a direct object, usually a noun phrase. Among the parts, "two factors" is the most suitable noun phrase and must therefore come first. "Often confused in the public minds" is a descriptive phrase that should immediately follow "two factors". Next, the relative clause "which suggest the need for an international language" completes the idea. This means the overall order after the introduction is R P Q S.

Step-by-Step Solution:
Step 1: Place R "two factors" after "We can think of" to get "We can think of two factors". Step 2: Add P "often confused in the public minds" so that it describes "two factors". The sentence now reads "We can think of two factors, often confused in the public minds". Step 3: Attach Q "which suggest the need for". This sets up what those factors imply. Step 4: Finish with S "an international language", giving the object of that need. Step 5: The final sentence is "We can think of two factors, often confused in the public minds, which suggest the need for an international language."

Verification / Alternative check:
Check the chosen order against the options. The sequence R P Q S corresponds to option B. If you try alternative orders such as P R Q S, you get "We can think of often confused in the public minds two factors", which is ungrammatical, because the descriptive phrase P should not come before the noun it describes. Similarly, starting with Q or S would leave "We can think of" without a proper direct object for too long.

Why Other Options Are Wrong:
- "P R Q S": begins with an adverbial phrase "often confused in the public minds" immediately after "We can think of", leaving the sentence without a clear object until later.
- "R Q S P": would result in "two factors which suggest the need for an international language often confused in the public minds", where the descriptive phrase appears at the end and makes the sentence clumsy.
- "S Q R P": starts with "an international language" after "We can think of", which changes the meaning and does not suit the phrase "two factors often confused".

Common Pitfalls:
Many learners overlook that descriptive phrases like "often confused in the public minds" must be attached directly to the noun they describe, which is "two factors" in this case. A good rule of thumb is that adjectives and descriptive phrases should not be separated from the nouns they modify by unrelated clauses. Also, when you see "which", it usually starts a relative clause that should follow the noun it refers to.

Final Answer:
The correct sequence is R P Q S, producing the sentence "We can think of two factors, often confused in the public minds, which suggest the need for an international language."