Cloze passage (birds): In the clause "... peculiar to the West, and ______ new to him, keeping him constantly on the "qui vive"", which connector best completes the blank?

Introduction / Context:
This cloze question continues the same descriptive passage about birds. The writer explains that the species and genera are peculiar to the West and draws a consequence from that fact. The blank is filled by a connector that shows a result, not a cause or condition. Understanding the logical relationship between the two parts of the sentence is the key to answering correctly.

Given Data / Assumptions:
- Relevant portion: "peculiar to the West, and ______ new to him, keeping him constantly on the "qui vive"." - Options: therefore, because, if, for. - "Peculiar to the West" means the species are found only or mainly in the West. - "New to him" is the natural consequence for a rambler from another region.

Concept / Approach:
"Therefore" is used to introduce a result or consequence of a previously mentioned fact. Since the birds are peculiar to the West, they are consequently new to the rambler. "Because" introduces a reason for something that follows, "if" indicates condition, and "for" is rarely used as a simple conjunction in this sort of modern prose. Thus, the sentence needs a word that expresses "as a result", making "therefore" the best choice.

Step-by-Step Solution:
Step 1: Identify the logical relation between "peculiar to the West" and "new to him". Step 2: Recognise that the second is a natural result of the first, not the cause. Step 3: "Therefore" means "for that reason" or "as a result". Applying it gives a smooth reading. Step 4: Test "because". It would produce "peculiar to the West, and because new to him", which is awkward and incomplete without a main clause. Step 5: Test "if". It would suggest a conditional meaning that the passage does not support. Step 6: Test "for". It would sound old fashioned and still not clearly convey the result relationship in this specific structure.

Verification / Alternative check:
Read the full sentence: "Most interesting of all to the rambler on avian lore intent is the fact that there are many species and genera that are peculiar to the West, and therefore new to him, keeping him constantly on the "qui vive"." The adverb "therefore" connects the two ideas in a clear cause and effect sequence. Replacing it with any other option either breaks the grammar or weakens the logic of the sentence.

Why Other Options Are Wrong:
"Because" normally introduces a clause that explains a reason for another clause, not a descriptive phrase like "new to him" inside the same structure. "If" creates a conditional idea, which does not fit the descriptive, factual tone of the passage. "For" would need a different sentence structure to function as a conjunction and is not idiomatic in this position.

Common Pitfalls:
Many learners confuse "because" and "therefore" since both relate to cause and effect, but they are used from different directions. "Because" introduces the cause, while "therefore" introduces the result. When you see that the sentence is moving from cause to result, as in this passage, "therefore" is usually the correct choice.

Final Answer:
The correct connector is "therefore", giving "peculiar to the West, and therefore new to him".