Meaning: 'Estimate' means to roughly calculate or judge the value, number, quantity, or extent of something.

Wrong options:

• unfold: The verb 'unfold' means to open or spread out something that was folded, which does not relate to calculating numbers.
• figure: The verb 'figure' can mean to calculate, but it does not fit the infinitive structure 'to figure' in this context as well as 'to estimate' does.
• surveys: The noun 'surveys' does not fit here as it does not serve as a verb in the infinitive form and does not relate to the action of estimating.
• funds: The noun 'funds' refers to money available for spending, which does not fit the context of estimating numbers.

Correct answer: surveys

Explanation: The word 'surveys' is a plural noun that fits grammatically as it follows the verb 'regularly,' indicating the action the government takes. Contextually, it aligns with the idea of collecting data from households.

Meaning: 'Surveys' refer to systematic investigations or questionnaires designed to gather information.

Wrong options:

• unfold: The verb 'unfold' does not fit in this context as it does not relate to the action of collecting data from households.
• sell: The verb 'sell' does not fit here as it does not relate to the government's action of gathering information.
• figure: The noun 'figure' does not fit as it does not relate to the action of conducting surveys and is not in the correct form.
• funds: The noun 'funds' does not fit as it refers to money and does not relate to the action of surveying.

Correct answer: sell

Explanation: The word 'sell' is a verb that fits grammatically as it follows 'quickly,' maintaining the parallel structure with 'buy.' Contextually, it aligns with the action of disposing of old devices after purchasing new ones.

Meaning: 'Sell' means to exchange something for money, which fits the context of people getting rid of their old devices.

Wrong options:

• unfold: The verb 'unfold' does not fit here as it does not relate to the action of selling devices.
• figure: The verb 'figure' does not fit in this context as it does not relate to the action of selling and does not maintain the parallel structure.
• surveys: The noun 'surveys' does not fit as it does not relate to the action of selling and is not in the correct form.
• funds: The noun 'funds' does not fit as it refers to money and does not relate to the action of selling.