Meaning: 'Hisory' refers to the study of past events, particularly in human affairs, although it should be 'history.'

Wrong options:

• required: The word 'required' is a verb that indicates necessity, which does not fit as it does not relate to a noun describing a field or area of study.
• covering: The word 'covering' is a gerund that implies action or process, which does not fit as it does not describe a field of study.
• achievement: The word 'achievement' is a noun that refers to a successful result, which does not fit as it does not describe a field or area of study.
• sustainability: The word 'sustainability' refers to the ability to be maintained at a certain rate or level, which is unrelated to the context of dictionaries or language.
• leading: The word 'leading' is an adjective that describes something that is at the forefront, which does not fit as it does not describe a field of study.
• repulsed: The word 'repulsed' is a verb that indicates a strong feeling of disgust, which is irrelevant in this context.
• declaration: The word 'declaration' is a noun that refers to a formal announcement, which does not fit as it does not describe a field of study.

Correct answer: required

Explanation: The word 'required' is a past participle that indicates necessity, fitting grammatically as it describes the need for helpers in the compilation of the dictionary. It aligns with the context of the sentence, which discusses the resources needed for the dictionary's creation.

Meaning: 'Required' means that something was necessary or needed for a particular purpose.

Wrong options:

• hisory: The word 'hisory' is a misspelling of 'history' and does not fit grammatically or contextually as it does not relate to the action of compiling the dictionary.
• covering: The word 'covering' is a gerund that implies action, which does not fit as it does not indicate necessity in this context.
• achievement: The word 'achievement' is a noun that refers to a successful result, which does not fit as it does not indicate a requirement or necessity.
• sustainability: The word 'sustainability' refers to the ability to be maintained, which is unrelated to the context of needing helpers for compilation.
• leading: The word 'leading' is an adjective that describes something at the forefront, which does not fit as it does not indicate necessity.
• repulsed: The word 'repulsed' is a verb indicating a strong feeling of disgust, which is irrelevant in this context.
• detail: The word 'detail' is a noun that refers to a specific item or aspect, which does not fit as it does not indicate a requirement.

Correct answer: detail

Explanation: The word 'detail' is a noun that refers to the specifics or particulars of something. It fits grammatically as it describes how each word was defined in the dictionary, aligning with the context of thoroughness in definitions.

Meaning: 'Detail' refers to the individual features or facts about something, indicating thoroughness in the definitions provided.

Wrong options:

• hisory: The word 'hisory' is a misspelling of 'history' and does not fit grammatically or contextually as it does not relate to the manner of defining words.
• required: The word 'required' is a verb that indicates necessity, which does not fit as it does not describe the manner of definition.
• covering: The word 'covering' is a gerund that implies action, which does not fit as it does not describe the specifics of definitions.
• achievement: The word 'achievement' is a noun that refers to a successful result, which does not fit as it does not describe the manner of defining words.
• sustainability: The word 'sustainability' refers to the ability to be maintained, which is unrelated to the context of defining words.
• leading: The word 'leading' is an adjective that describes something at the forefront, which does not fit as it does not describe the manner of definition.
• repulsed: The word 'repulsed' is a verb indicating a strong feeling of disgust, which is irrelevant in this context.

Correct answer: covering

Explanation: The word 'covering' is a gerund that indicates the action of including or encompassing. It fits grammatically and contextually as it describes how the definitions were illustrated with quotations from various fields of knowledge.

Meaning: 'Covering' means to include or encompass a range of topics or areas.

Wrong options:

• hisory: The word 'hisory' is a misspelling of 'history' and does not fit grammatically or contextually as it does not relate to the action of including.
• required: The word 'required' is a verb that indicates necessity, which does not fit as it does not describe the action of including quotations.
• detail: The word 'detail' is a noun that refers to specifics, which does not fit as it does not describe the action of including or encompassing.
• achievement: The word 'achievement' is a noun that refers to a successful result, which does not fit as it does not describe the action of including quotations.
• sustainability: The word 'sustainability' refers to the ability to be maintained, which is unrelated to the context of including quotations.
• leading: The word 'leading' is an adjective that describes something at the forefront, which does not fit as it does not describe the action of including.
• repulsed: The word 'repulsed' is a verb indicating a strong feeling of disgust, which is irrelevant in this context.

Correct answer: achievement

Explanation: The word 'achievement' is a noun that refers to a successful result or accomplishment. It fits grammatically and contextually as it describes the dictionary's significance as a scholarly work, emphasizing its extensive and complex nature.

Meaning: 'Achievement' refers to something accomplished, especially by hard work or skill.

Wrong options:

• hisory: The word 'hisory' is a misspelling of 'history' and does not fit grammatically or contextually as it does not describe a successful result.
• required: The word 'required' is a verb that indicates necessity, which does not fit as it does not describe the nature of the dictionary.
• covering: The word 'covering' is a gerund that implies action, which does not fit as it does not describe a successful result or accomplishment.
• detail: The word 'detail' is a noun that refers to specifics, which does not fit as it does not describe a successful result or accomplishment.
• sustainability: The word 'sustainability' refers to the ability to be maintained, which is unrelated to the context of describing the dictionary's significance.
• leading: The word 'leading' is an adjective that describes something at the forefront, which does not fit as it does not describe a successful result.
• repulsed: The word 'repulsed' is a verb indicating a strong feeling of disgust, which is irrelevant in this context.