Meaning: 'Around' means in a circular direction or in various places within a certain area, indicating the nature of the movement while sleepwalking.

Wrong options:

• beyond: 'Beyond' implies going further than a certain point, which does not fit the context of sleepwalking as it suggests a more defined boundary.
• aside: 'Aside' indicates a position next to something, which does not convey the idea of movement that is typical in sleepwalking.
• beside: 'Beside' means next to something, which does not accurately describe the wandering nature of sleepwalking.

Correct answer: certain

Explanation: The word 'certain' is appropriate here as it refers to specific times without being overly precise, fitting well with the context of sleepwalking occurring at particular intervals during the night.

Meaning: 'Certain' means specific but not explicitly defined, indicating that sleepwalking happens at particular times during the night.

Wrong options:

• other: 'Other' suggests an alternative but does not specify any particular times, making it less suitable in this context.
• some: 'Some' implies an indefinite quantity, which is too vague for the context of sleepwalking occurring at specific times.
• few: 'Few' indicates a small number, which does not align with the idea of sleepwalking happening at specific times.

Correct answer: what

Explanation: The word 'what' is the correct choice as it refers to the actions taken during sleepwalking, fitting grammatically and contextually as it seeks to clarify the nature of the sleepwalker's experience.

Meaning: 'What' is used to inquire about something, in this case, the actions that the sleepwalker does not remember.

Wrong options:

• where: 'Where' asks about a location, which does not fit the context of recalling actions taken during sleepwalking.
• when: 'When' refers to time, which is not relevant to the actions performed, making it an incorrect choice.
• how: 'How' inquires about the manner of actions, which does not align with the context of forgetting specific actions.

Correct answer: Others

Explanation: The word 'Others' is suitable here as it refers to additional types of unusual sleep behavior, maintaining grammatical consistency and context with the preceding sentence.

Meaning: 'Others' refers to additional items or people not previously mentioned, indicating that there are more types of sleep behaviors apart from sleepwalking.

Wrong options:

• The other: 'The other' implies a singular alternative, which does not fit as the sentence refers to multiple types of behaviors.
• Another: 'Another' suggests one more item, which is not appropriate since the context indicates multiple behaviors.
• Other: 'Other' is grammatically incorrect in this context as it lacks the plural form needed to refer to multiple types.