In the following sentence improvement question, choose the alternative that best replaces the underlined expression so that the sentence becomes correct and idiomatic: "Sita did not so far as blink when she heard she had won the scholarship to Cambridge."

Introduction / Context:
This sentence improvement question tests your knowledge of fixed idiomatic expressions in English. The sentence describes Sita's reaction on hearing that she had won a scholarship to Cambridge and focuses on how little she reacted. To express this idea naturally, English uses a very specific phrase, and the exam checks whether you can recognise and select that idiom correctly.

Given Data / Assumptions:

• Original sentence: "Sita didn't so far as blink when she heard she had won the scholarship to Cambridge."
• The underlined part is "so far as blink."
• The intended meaning is that she did not blink at all; she did not show even the smallest reaction.
• We must choose the option that makes the sentence grammatical and idiomatic.

Concept / Approach:
The standard English idiom is "not so much as blink," which means "not even blink once" or "not show the slightest reaction." The words "so far as" are not used in this structure. While "as far as" has a different, separate meaning (for example, "as far as I know"), it does not combine with "blink" in the way we need here. Therefore, the phrase must be corrected to "so much as blink" to convey the intended minimal reaction.

Step-by-Step Solution:
Step 1: Identify the key idea: Sita showed no reaction at all, not even blinking. Step 2: Recall the idiomatic pattern: "did not so much as + base verb." Step 3: Replace "so far as" with "so much as" to form "did not so much as blink." Step 4: Read the whole sentence: "Sita did not so much as blink when she heard she had won the scholarship to Cambridge." Step 5: Confirm that the sentence is now both grammatically correct and idiomatic.

Verification / Alternative check:
Compare with similar examples: "He did not so much as smile at the joke," or "She did not so much as say thank you." In each case, "so much as" emphasises that the smallest expected action did not happen. If we tried "did not so far as blink" or "did not as far as blink," these phrases would sound wrong to a native speaker because they are not recognised idioms. This confirms that "so much as" is the only acceptable correction here.

Why Other Options Are Wrong:

• as far as: Used to introduce the extent of knowledge or distance, as in "As far as I know," not to intensify a verb of reaction like "blink."
• as good as: Means "practically" or "almost," as in "The game is as good as over," and does not fit the structure with "blink."
• No improvement: The phrase "so far as blink" is unidiomatic and incorrect, so the sentence definitely needs improvement.

Common Pitfalls:
Learners sometimes confuse "so much as" with "as much as" or "as far as" because these phrases look similar. However, only "so much as" is used in the special structure "did not so much as + verb" to emphasise that even a tiny expected action did not occur. Remember that idioms often cannot be altered without becoming incorrect; changing even one word can spoil the expression.

Final Answer:
The correct improvement is so much as, giving the sentence: Sita did not so much as blink when she heard she had won the scholarship to Cambridge.