Understanding Sentence Structure and Verb Forms

The question asks us to select the most appropriate option to improve the underlined segment in the sentence: "Eighty girls sat there at four long tables, doing their homework by candlelight." We need to examine the grammatical correctness and clarity of the underlined part and the given options.

Analyzing the Original Sentence

The original sentence is: "Eighty girls sat there at four long tables, doing their homework by candlelight."

Let's break down the structure:

• "Eighty girls sat there at four long tables" is the main clause.
• ", doing their homework by candlelight" is a participial phrase modifying the subject "Eighty girls".

A participial phrase using the present participle (verb + -ing) like "doing" can be used to describe an action happening at the same time as the main verb (sat). This construction is grammatically correct and commonly used to add detail about the simultaneous activity of the subject.

• "doing" is the present participle of the verb "do".
• "their homework" is the direct object of "doing". The possessive pronoun "their" correctly refers to the plural subject "Eighty girls".
• "by candlelight" is a prepositional phrase indicating the means or condition under which the action was performed.

The phrase "doing their homework by candlelight" correctly describes the activity the girls were engaged in while sitting there.

Evaluating the Options for Sentence Improvement

Let's look at the alternative options provided:

1. to have done their homework with: This option uses a perfect infinitive ("to have done"). A perfect infinitive usually refers to an action completed before another point in time. Here, the homework was being done *while* they were sitting, not *before*. Also, "with candlelight" is an awkward phrasing compared to the standard idiom "by candlelight". This option is grammatically incorrect and stylistically poor in this context.
2. no improvement required: This option suggests that the original sentence is already correct and doesn't need modification.
3. to doing their homework by: This option uses the construction "to doing". In standard English grammar, the infinitive form is "to do", not "to doing". The structure "to + present participle" is generally incorrect. This option is grammatically flawed.
4. doing its homework by: This option uses the possessive pronoun "its". "Its" is used for singular nouns (especially things or animals) or sometimes for collective nouns. The subject "Eighty girls" is plural and refers to people. The correct possessive pronoun for a plural group of people is "their". Therefore, using "its" here is grammatically incorrect.

Conclusion: Why 'no improvement required' is Correct

Based on the analysis, the original sentence "Eighty girls sat there at four long tables, doing their homework by candlelight" uses a grammatically correct participial phrase ("doing their homework by candlelight") to describe the simultaneous action of the girls. Each of the alternative options introduces grammatical errors or awkward phrasing.

Therefore, the original sentence is correctly structured and phrased, and no improvement is required.

Revision Table: Key Grammatical Points

Additional Information on Participle Phrases

A participle phrase acts like an adjective, adding information about the noun or pronoun it modifies. It can come at the beginning, middle, or end of a sentence. When it follows the noun, as in the original sentence, it often describes an action happening concurrently.

Examples of sentences using present participle phrases:

• The children played in the park, laughing loudly. (Laughing loudly describes how the children played)
• He sat on the bench, reading a book. (Reading a book describes what he was doing while sitting)
• The car sped down the road, leaving a trail of dust. (Leaving a trail describes what the car did as it sped)

In the given sentence, "doing their homework by candlelight" clearly and correctly describes the activity of the "Eighty girls" while they "sat there".