A.I. Explanation:

Correct answer: place

Explanation: The word 'place' fits grammatically as it indicates a location where desertification occurs, aligning with the context of the sentence about the edges of existing deserts. It is a noun that complements the verb 'takes' in this context, making it the correct choice.

Meaning: 'Place' refers to a specific location or position, indicating where the process of desertification happens.

Wrong options:

• part: 'Part' implies a portion of something and does not convey the specific location needed in this context.
• care: 'Care' refers to the act of looking after something, which does not fit the context of a process occurring in a location.
• action: 'Action' denotes a deed or act, which is not suitable here as the sentence requires a noun indicating a location.

Correct answer: on

Explanation: The preposition 'on' is appropriate here as it indicates the relationship between the animals and the plants they feed on, fitting grammatically and contextually with the sentence structure.

Meaning: 'On' indicates a position above or in contact with something, in this case, the animals living in association with the drought-resistant plants.

Wrong options:

• in: 'In' suggests being inside something, which does not accurately describe the relationship between the animals and the plants in this context.
• with: 'With' implies accompaniment but does not convey the specific feeding relationship required here.
• down: 'Down' indicates a direction or position lower than something else, which is not relevant to the context of living on plants.

Correct answer: too

Explanation: The word 'too' functions as an adverb indicating excess, which fits logically in the context of the sentence, suggesting that an excessive number of animals feeding on the plants leads to their death.

Meaning: 'Too' means 'excessively' or 'more than is desirable,' highlighting the negative impact of having many animals feed on the plants.

Wrong options:

• much: 'Much' is typically used with uncountable nouns and does not fit here as it does not convey the idea of excess in the same way as 'too.'
• rather: 'Rather' indicates a preference or degree but does not imply excess, making it unsuitable for this context.
• quite: 'Quite' suggests a moderate degree, which does not convey the sense of excess needed in this sentence.

Correct answer: turns into

Explanation: The phrase 'turns into' is a phrasal verb that indicates transformation, fitting grammatically and contextually as it describes the change of land into desert.

Meaning: 'Turns into' means to change from one state to another, in this case, the land becoming desert.

Wrong options:

• turn out: 'Turn out' implies a result or conclusion, which does not fit the context of transformation described in the sentence.
• turn away: 'Turn away' suggests a rejection or avoidance, which is not relevant to the process of land changing into desert.
• turns up: 'Turns up' indicates an appearance or arrival, which does not convey the transformation aspect required in this context.

Correct answer: are created

Explanation: The phrase 'are created' is in the passive voice, which is appropriate here as it indicates that new deserts are formed as a result of the described process, fitting grammatically and contextually with the sentence.

Meaning: 'Are created' means that new deserts come into existence, emphasizing the ongoing nature of this process.

Wrong options:

• create: 'Create' is an active verb form that does not fit the passive construction needed in this context.
• have been created: 'Have been created' suggests a completed action in the past, which does not align with the ongoing process described in the sentence.
• has created: 'Has created' is also in the active voice and does not match the passive structure required here.