The board of trustees have approved the annual budget unanimously. (Improve)

• A. has approved (Answer)
• B. had approved
• C. will have approved
• D. No improvement

'Board of trustees' acts as a single decision-making body here, taking a singular verb: 'has approved'. 'Have' incorrectly treats the board as multiple independent actors.

Not only does she sing beautifully, she also dances gracefully. (Improve)

• A. but she also dances gracefully (Answer)
• B. and she also dances gracefully
• C. but also she dances gracefully
• D. No improvement

'Not only' must be paired with 'but also' (or 'but...also'), not just 'also'. Correct: 'Not only does she sing beautifully, but she also dances gracefully'. Omitting 'but' is a frequent oversight in fast writing.

Scarcely had the meeting begun, the fire alarm rang. (Improve)

• A. when the fire alarm rang (Answer)
• B. than the fire alarm rang
• C. as the fire alarm rang
• D. No improvement

'Scarcely/hardly...when' is the fixed correlative pairing ('than' pairs with 'no sooner'). Correct: 'Scarcely had the meeting begun when the fire alarm rang'.

Such was the intensity of the storm that entire villages were washed away. (Improve)

• A. the intensity was such
• B. was such the intensity
• C. No improvement (Answer)
• D. such the intensity was

'Such was the intensity...that' is a correctly formed emphatic inversion, parallel to 'So intense was the storm that...'. No improvement — reserved to test whether students distrust unfamiliar but valid inverted structures.

The two witnesses' testimonies, though largely consistent, was found to differ on one crucial point. (Improve)

• A. were found to differ (Answer)
• B. was being found to differ
• C. had found to differ
• D. No improvement

The subject 'The two witnesses' testimonies' is plural. The intervening concessive clause 'though largely consistent' distances the verb from its true subject, tempting a singular 'was'. Correct: 'were found to differ on one crucial point'.

Neither the minister nor his aides was willing to comment on the allegations. (Improve)

• A. were willing (Answer)
• B. is willing
• C. has been willing
• D. No improvement

With 'neither...nor', the verb agrees with the nearer subject. Since 'his aides' (plural) is closer to the verb than 'the minister' (singular), the correct form is 'were willing to comment'.

It is high time the government should take decisive action against the smugglers. (Improve)

• A. the government takes decisive action
• B. the government took decisive action (Answer)
• C. No improvement
• D. the government will take decisive action

'It is high time' is followed by the simple past tense (a subjunctive-like usage), not 'should + infinitive'. Correct: 'It is high time the government took decisive action'. Inserting 'should' is a common but incorrect embellishment.

The evidence having thoroughly examined, the jury reached a verdict quickly. (Improve)

• A. having been thoroughly examined (Answer)
• B. having examined thoroughly
• C. having through examination
• D. No improvement

'The evidence' cannot perform the act of examining — it must receive the action. The absolute construction needs the passive form: 'having been thoroughly examined'. Correct: 'The evidence having been thoroughly examined, the jury reached a verdict quickly'.

So thoroughly he had prepared for the interview that no question could stump him. (Improve)

• A. had he prepared (Answer)
• B. did he prepared
• C. he had prepare
• D. No improvement

Fronting the intensifying phrase 'So thoroughly' requires subject-auxiliary inversion in the following clause: 'had he prepared', not normal word order 'he had prepared'.

Not until she had submitted her resignation did she feel a sense of relief. (Improve)

• A. she did feel a sense of relief
• B. did she felt a sense of relief
• C. No improvement (Answer)
• D. she feel a sense of relief did

'Not until she had submitted her resignation' correctly triggers inversion in the main clause: 'did she feel a sense of relief'. Every element — tense and inversion — is correctly executed. No improvement — reserved as the final question to reward candidates who verify rather than assume.