Who had done the work? The correct passive voice of this sentence is :
By whom the work had done?
By whom had the work done?
By whom had the work been done?
Who the work had been done?
Explanation:
Correct Answer is: By whom had the work been done?

By whom the work had done?
By whom had the work done?
By whom had the work been done?
Who the work had been done?
Correct Answer is: By whom had the work been done?

Mr. Pat ____ all his time _____ national digaster. Option A: deprive, of , Option B: devoted, at , Option C: deals, to, Option D: devoted, to, correct answer is: devoted, to
What type of noun the word `infancy` is? Option A: Common , Option B: Abstract , Option C: Material, Option D: Collective, correct answer is: Abstract
Hardly do I go to library. The underlined word is a/an -- Option A: noun , Option B: adverb , Option C: preposition, Option D: adjective, correct answer is: adverb
The noun of the word `sure` is- Option A: assurance , Option B: ensure , Option C: surety, Option D: sure, correct answer is: ensure
`Freedom` of speech is required in democracy. Option A: Adjective , Option B: Noun , Option C: Adverb, Option D: Preposition, correct answer is: Noun