Meaning: 'Make' means to create or cause something to exist, in this case, the abstract should create a coherent understanding on its own.

Wrong options:

• get: 'Get' implies obtaining or receiving, which does not convey the idea of creating coherence in this context.
• give: 'Give' suggests providing something to someone, which does not fit the requirement of the abstract being self-contained.
• take: 'Take' implies removing or accepting something, which does not align with the need for the abstract to be self-sufficient.

Correct answer: content

Explanation: The noun 'content' refers to the material or subject matter contained within the abstract, making it the most suitable choice. It aligns with the context of highlighting key areas of research.

Meaning: 'Content' means the information or topics covered in a document, which in this case refers to the main subjects of the research.

Wrong options:

• contemplate: 'Contemplate' means to think deeply about something, which does not fit the context of describing what the abstract highlights.
• account: 'Account' refers to a report or description of an event, which does not accurately represent the focus on key areas of research.
• comment: 'Comment' implies a remark or observation, which does not align with the idea of summarizing the main subjects of the research.

Correct answer: in

Explanation: The preposition 'in' is used to indicate the context or location of the length of the abstract, making it the correct choice. It fits grammatically and contextually with the phrase 'in length.'

Meaning: 'In' indicates the measurement or extent of something, here referring to the length of the abstract.

Wrong options:

• from: 'From' suggests a starting point, which does not fit the context of describing the length of the abstract.
• within: 'Within' implies being inside something, which does not accurately describe the length of the abstract.
• to: 'To' indicates direction or destination, which does not apply to the context of measuring length.

Correct answer: it is placed

Explanation: The phrase 'it is placed' is grammatically correct and indicates the position of the abstract in relation to the paper. It fits contextually as it describes the abstract's location in the document.

Meaning: 'It is placed' means that the abstract is positioned at a specific point in the paper, specifically at the beginning.

Wrong options:

• it is transferring: This phrase is grammatically incorrect in this context, as 'transferring' does not relate to the placement of the abstract.
• it has omitted: This phrase suggests something has been left out, which does not apply to the context of where the abstract is located.
• it started: This phrase implies the beginning of an action, which does not accurately describe the static position of the abstract.

Correct answer: once

Explanation: The adverb 'once' indicates a specific time after which something occurs, fitting grammatically and contextually as it refers to the timing of writing the abstract after reaching conclusions.

Meaning: 'Once' means at the time that or as soon as, indicating the condition under which the abstract should be written.

Wrong options:

• then: 'Then' suggests a sequence of events, which does not convey the conditional aspect of writing the abstract after conclusions are reached.
• before: 'Before' indicates a prior time, which contradicts the requirement that the abstract should be written after the conclusions are clear.
• and: 'And' is a conjunction that connects ideas, which does not fit the context of indicating a specific timing for writing the abstract.