A.I. Explanation:

Correct answer: available

Explanation: The word 'available' is an adjective that describes the marks that can be earned for each part of the exam. It fits grammatically as it completes the phrase 'marks are available,' indicating the presence of marks for scoring.

Meaning: 'Available' means that something is present and can be used or obtained.

Wrong options:

• valuable: 'Valuable' is an adjective that describes worth but does not fit in the context of marks being present for scoring.
• spare: 'Spare' is an adjective that means extra or additional, which does not appropriately describe marks in this context.
• hours: 'Hours' is a noun that refers to a unit of time, which does not fit grammatically in this sentence.
• time: 'Time' is a noun that refers to the ongoing sequence of events, but it does not describe the marks in this context.
• look: 'Look' is a verb that means to direct one's gaze, which does not fit the grammatical structure of the sentence.
• writing: 'Writing' is a gerund that refers to the act of composing text, which does not relate to the marks being discussed.

Correct answer: answering

Explanation: The word 'answering' is a gerund that functions as a noun in this context, referring to the act of providing a response to a question. It fits grammatically and contextually as it describes what the student should not spend too much time doing.

Meaning: 'Answering' refers to the act of responding to a question or prompt.

Wrong options:

• valuable: 'Valuable' is an adjective that describes worth but does not fit as a noun in this context.
• spare: 'Spare' is an adjective that means extra, which does not fit grammatically as it does not describe an action.
• look: 'Look' is a verb that means to direct one's gaze, which does not fit in the context of providing a response.
• writing: 'Writing' is a gerund that refers to the act of composing text, but it does not fit the context of answering a question specifically.

Correct answer: time

Explanation: The word 'time' is a noun that refers to the ongoing progression of events. It fits grammatically and contextually as it indicates the availability of time to return to the previous question if needed.

Meaning: 'Time' refers to the measurable period during which actions or events occur.

Wrong options:

• valuable: 'Valuable' is an adjective that describes worth but does not fit as a noun in this context.
• spare: 'Spare' is an adjective that means extra, which does not fit grammatically as it does not refer to a measurable period.
• hours: 'Hours' is a plural noun that refers to units of time, but it does not fit the context of needing time in a general sense.

Correct answer: spare

Explanation: The word 'spare' is an adjective that describes something extra or additional. It fits grammatically and contextually as it indicates time that is not allocated to other tasks and can be used later.

Meaning: 'Spare' means extra or available for use when needed.

Wrong options:

• valuable: 'Valuable' is an adjective that describes worth but does not fit in the context of time that is extra.
• time: 'Time' is a noun that refers to the ongoing sequence of events, which does not fit as an adjective describing additional time.
• look: 'Look' is a verb that means to direct one's gaze, which does not fit in the context of describing time.

Correct answer: valuable

Explanation: The word 'valuable' is an adjective that describes something that has worth or importance. It fits grammatically and contextually as it emphasizes the significance of the time being discussed in the context of the exam.

Meaning: 'Valuable' means having worth or importance.

Wrong options:

• spare: 'Spare' is an adjective that means extra, which does not convey the importance of time in this context.
• time: 'Time' is a noun that refers to the ongoing sequence of events, which does not fit as an adjective describing the worth of time.
• hours: 'Hours' is a plural noun that refers to units of time, but it does not fit the context of describing the worth of time.