Meaning: Differences refer to the distinctions or variations between two or more entities.

Wrong options:

• confirmation: 'Confirmation' is a noun that implies validation or proof, which does not relate to the comparative context of cognitive abilities.
• arguments: 'Arguments' refers to reasons or statements made to support a point, which does not fit the context of identifying cognitive variations.
• equality: 'Equality' denotes a state of being equal, which contradicts the focus on differences between the two groups.

Correct answer: ability

Explanation: The word 'ability' is a noun that fits grammatically and contextually, as it refers to the capacity of children to perform cognitive tasks, which is the focus of the studies.

Meaning: Ability refers to the skill or capacity to do something.

Wrong options:

• confirmation: 'Confirmation' does not relate to the capacity to solve problems and is not a suitable noun in this context.
• differences: 'Differences' is already used in the first blank and does not fit here as it does not refer to a capacity or skill.
• arguments: 'Arguments' does not pertain to cognitive skills and is irrelevant in this context.

Correct answer: intention

Explanation: The term 'intention' is a noun that fits grammatically and contextually, as it describes the purpose behind the studies, which is to understand the impact of bilingualism.

Meaning: Intention refers to a purpose or aim behind an action.

Wrong options:

• confirmation: 'Confirmation' does not relate to the purpose of the studies and is not appropriate in this context.
• arguments: 'Arguments' does not convey the purpose of the studies and is irrelevant here.
• function: 'Function' refers to the role or activity of something, which does not fit as the purpose of the studies.

Correct answer: function

Explanation: The word 'function' is a noun that fits grammatically and contextually, as it refers to the role of cognitive processes in development, which is a key aspect of the studies.

Meaning: Function refers to the specific role or activity of something within a system.

Wrong options:

• confirmation: 'Confirmation' does not relate to the role of cognitive processes and is not suitable in this context.
• arguments: 'Arguments' does not pertain to cognitive processes and is irrelevant here.
• intention: 'Intention' is already used in the third blank and does not fit as it does not describe a role or function.