Meaning: 'Discern' means to detect or distinguish something, particularly through careful observation or analysis.

Wrong options:

• concern: The word 'concern' implies worry or interest, which does not fit the context of tasting characteristics.
• disregard: 'Disregard' means to ignore or pay no attention to, which contradicts the idea of recognizing taste characteristics.
• disarrange: 'Disarrange' means to disrupt the order of something, which is irrelevant to the context of tasting.

Correct answer: alter

Explanation: The word 'alter' is a verb that means to change or modify, which is appropriate here as it describes how variations in temperature and precipitation affect the balance of chemicals in tea. It fits grammatically and contextually within the sentence.

Meaning: 'Alter' means to change or adjust something, particularly in a way that affects its nature or function.

Wrong options:

• poster: 'Poster' refers to a printed picture or notice, which does not relate to the context of changing chemical balances.
• altar: 'Altar' is a structure used for religious rituals, which is irrelevant to the context of tea and its chemical composition.
• deter: 'Deter' means to discourage or prevent, which does not fit the context of modifying the balance of chemicals.

Correct answer: board

Explanation: The word 'board' is used here as a noun referring to a group of people or an organization, which fits the context of regions affected by climate change. It is grammatically correct and aligns with the idea of tea yields being influenced across different areas.

Meaning: 'Board' in this context refers to a governing body or group that oversees or manages something, which can be interpreted as regions or areas affected by climate change.

Wrong options:

• river: 'River' refers to a natural watercourse, which does not fit the context of regions affected by climate change.
• street: 'Street' refers to a public road, which is not relevant to the discussion of tea yields and climate change.
• border: 'Border' refers to the edge or boundary of an area, which does not convey the intended meaning of regions affected by climate change.

Correct answer: erosion

Explanation: The word 'erosion' fits grammatically and contextually as it refers to the process of soil being worn away, which is directly related to the effects of intense rains on soil. It accurately describes the damage caused to root development in tea plants.

Meaning: 'Erosion' means the gradual destruction or diminution of something, particularly soil, due to natural forces like water or wind.

Wrong options:

• compression: 'Compression' refers to the act of pressing something together, which does not relate to the context of soil damage.
• diffusion: 'Diffusion' refers to the spreading of something more widely, which is not relevant to the context of soil degradation.
• conversion: 'Conversion' means changing something into a different form, which does not fit the context of soil being damaged.

Correct answer: reproduce

Explanation: The word 'reproduce' is a verb that means to produce again or to breed, which fits the context of insects being able to survive and multiply. It is grammatically correct and logically follows the idea of increased insect populations due to higher temperatures.

Meaning: 'Reproduce' means to create offspring or to breed, particularly in the context of living organisms.

Wrong options:

• conduce: 'Conduce' means to lead to a result or contribute to something, which does not fit the context of insects multiplying.
• educate: 'Educe' means to draw out or bring forth, which is not relevant to the context of insect populations.
• adduce: 'Adduce' means to cite as evidence, which does not relate to the context of insects and their breeding.