Meaning: 'Becoming' refers to the process of changing or developing into a particular state or condition, in this case, a happy and helpful employee.

Wrong options:

• becomes: 'Becomes' is a simple present tense verb that does not convey the ongoing process implied in the sentence.
• became: 'Became' is the past tense form, which does not fit the present context of effort leading to a current state.
• to become: 'To become' is an infinitive form that does not grammatically fit in the structure of the sentence.

Correct answer: erodes

Explanation: The word 'erodes' is appropriate as it indicates a gradual reduction of energy over time, fitting the context of diminishing resources due to effort. It aligns with the overall sentiment of the sentence regarding the impact of effort on energy levels.

Meaning: 'Erodes' means to gradually wear away or diminish, in this case, referring to the depletion of energy needed for work.

Wrong options:

• concludes: 'Concludes' implies finishing or ending, which does not relate to the gradual loss of energy described.
• shared: 'Shared' suggests distribution or commonality, which does not fit the context of energy being diminished.
• envisages: 'Envisages' means to imagine or foresee, which is unrelated to the concept of energy reduction.

Correct answer: at

Explanation: The preposition 'at' is correctly used to indicate a specific point in time, 'at the end of the day,' which is a common expression. This fits grammatically and contextually within the sentence structure.

Meaning: 'At' indicates a specific location or time, in this case, referring to the conclusion of the workday.

Wrong options:

• since: 'Since' indicates a starting point in time, which does not fit the context of a specific moment like 'the end of the day.'
• on: 'On' is typically used for days or dates, making it grammatically incorrect in this context.
• by: 'By' suggests a deadline or limit, which does not convey the same meaning as 'at the end of the day.'

Correct answer: where

Explanation: The word 'where' is appropriate as it introduces a clause that specifies the emotional state of employees, fitting grammatically and contextually within the sentence. It indicates the location of their emotional state.

Meaning: 'Where' refers to the place or situation in which something occurs, in this case, the emotional state of employees.

Wrong options:

• which: 'Which' is a relative pronoun that does not fit the context of specifying emotional states.
• when: 'When' refers to time, which does not appropriately describe the emotional context needed here.
• that: 'That' is a restrictive relative pronoun but does not convey the same specificity regarding emotional states as 'where.'