Meaning: 'Planted' means to place a seed or plant in the ground so that it can grow.

Wrong options:

• implanted: Implanted suggests insertion into a body or system, which is not relevant here as it implies a medical context.
• supplanted: Supplanted means to replace or take the place of something, which does not fit the context of growing clones.
• fused: Fused implies joining two or more things together, which does not apply to the act of growing clones.

Correct answer: blows

Explanation: The word 'blows' is the present tense form of the verb that indicates the action of air movement, which is suitable here as it describes how ozone enters the rural areas. It fits contextually and maintains the correct tense.

Meaning: 'Blows' means to move air or gas, often used to describe wind or air currents.

Wrong options:

• climbs: Climbs suggests an upward movement, which does not apply to the context of ozone entering an area.
• stays: Stays implies remaining in one place, which does not accurately describe the action of ozone entering the environment.
• strikes: Strikes suggests a sudden impact, which is not appropriate for describing the movement of ozone.

Correct answer: overwhelming

Explanation: The word 'overwhelming' is an adjective that describes something that is very powerful or intense, fitting perfectly in this context to indicate the significant impact of ozone on tree growth. It aligns with the tone and meaning of the sentence.

Meaning: 'Overwhelming' means having a strong effect or being very intense, indicating that this factor greatly influences tree growth.

Wrong options:

• overrated: Overrated means having a higher opinion than is deserved, which does not fit the context of discussing a significant factor.
• overacting: Overacting refers to exaggerated performance, which is irrelevant in this scientific context.
• overestimated: Overestimated means judged to be greater than it is, which contradicts the intended meaning of a significant factor.

Correct answer: pay

Explanation: The word 'pay' is used here as a verb meaning to suffer or incur a cost, which fits grammatically and contextually to indicate that rural areas are affected by urban pollution. It maintains the correct tense and meaning in the sentence.

Meaning: 'Pay' in this context means to bear the consequences or costs of something, indicating that rural areas are negatively impacted by urban pollution.

Wrong options:

• quote: Quote means to repeat someone else's words, which does not fit the context of discussing consequences.
• refund: Refund refers to returning money, which is not relevant in this context of environmental impact.
• copy: Copy means to reproduce something, which does not apply to the idea of bearing consequences.