Meaning: 'With' indicates a connection or involvement, suggesting that marketing is concerned with customers.

Wrong options:

• by: 'By' suggests a means of doing something, which does not fit the context of dealing with customers directly.
• for: 'For' implies purpose or benefit, which does not accurately convey the interaction implied in the sentence.
• in: 'In' indicates location or inclusion, which does not appropriately describe the relationship between marketing and customers.

Correct answer: current

Explanation: The adjective 'current' refers to customers who are presently engaged with the business, fitting grammatically and contextually as it describes the target group for retention and growth in marketing.

Meaning: 'Current' means existing or present, referring to customers that the business is actively serving.

Wrong options:

• future: 'Future' refers to customers who may engage later, which does not fit the context of retaining existing customers.
• past: 'Past' implies customers who are no longer engaged, which contradicts the goal of keeping customers.
• previous: 'Previous' suggests customers who were once engaged but are not currently, which does not align with the intent of the sentence.

Correct answer: success

Explanation: The noun 'success' fits grammatically as it serves as the object of the preposition 'for,' indicating the outcome that sound marketing aims to achieve. This aligns with the overall context of the sentence regarding organizational goals.

Meaning: 'Success' refers to the achievement of desired outcomes or goals, particularly in a business context.

Wrong options:

• succeed: 'Succeed' is a verb form that does not fit the grammatical structure required here as it cannot serve as the object of 'for.'
• succeeded: 'Succeeded' is the past tense of the verb and does not fit the context as it cannot function as a noun in this sentence.
• successful: 'Successful' is an adjective and does not fit grammatically as it cannot serve as the object of 'for'.

Correct answer: use

Explanation: The verb 'use' is in the present tense, which is appropriate here as it describes the ongoing action of large firms employing marketing strategies. This aligns with the grammatical structure of the sentence.

Meaning: 'Use' means to employ or utilize something, indicating that firms actively engage in marketing practices.

Wrong options:

• using: 'Using' is a gerund form that does not fit the grammatical structure required here as it cannot serve as the main verb in this context.
• useful: 'Useful' is an adjective and does not fit grammatically as it cannot serve as the main verb in this sentence.
• used: 'Used' is the past tense form of the verb and does not fit the present context of the sentence.

Correct answer: lot

Explanation: The noun 'lot' is used informally to indicate a large amount or number, fitting grammatically and contextually as it conveys the idea of having substantial knowledge about marketing.

Meaning: 'Lot' means a large amount or number of something, suggesting that the reader has considerable knowledge of marketing.

Wrong options:

• plenty: 'Plenty' is a noun that implies abundance but does not fit the grammatical structure as well as 'lot' does in this context.
• much: 'Much' is typically used with uncountable nouns and does not fit well with 'about marketing' in this context.
• deal: 'Deal' is not commonly used in this context to indicate quantity and does not fit grammatically.

Correct answer: mall

Explanation: The noun 'mall' fits grammatically as it refers to a place where shopping occurs, aligning with the context of observing marketing results in a physical location.

Meaning: 'Mall' refers to a large shopping center where various stores are located, indicating a place where marketing is evident.

Wrong options:

• ground: 'Ground' does not refer to a shopping location and does not fit the context of the sentence.
• trolley: 'Trolley' refers to a cart used for shopping, which does not fit as a location for observing marketing results.
• space: 'Space' is too vague and does not specifically indicate a shopping area, making it unsuitable in this context.