Meaning: 'Its' is used to indicate that something belongs to or is associated with a thing previously mentioned, in this case, the insect's legs.

Wrong options:

• her: 'Her' is a possessive pronoun used for females, which does not apply here as the insect is not specified as female.
• there: 'There' is an adverb indicating a place, which does not fit grammatically or contextually in this sentence.
• his: 'His' is a possessive pronoun used for males, which is inappropriate here as the gender of the insect is not specified.

Correct answer: abandoned

Explanation: The word 'abandoned' is the past participle form that fits grammatically in the passive voice construction of the sentence, indicating that the walking style is no longer used when faced with oversized food. It aligns with the tense and context of the sentence.

Meaning: 'Abandoned' means to give up or stop using something, indicating that the ants stop using the tripod walking style when they encounter large food items.

Wrong options:

• abandons: 'Abandons' is the present tense form, which does not fit the past context of the sentence.
• abandoning: 'Abandoning' is the present participle form, which does not fit the grammatical structure required here.
• abandoned: This option is already the correct answer.

Correct answer: have seen

Explanation: The phrase 'have seen' is in the present perfect tense, which is appropriate here as it indicates an action that has relevance to the present moment. It aligns with the context of the researchers discussing their findings.

Meaning: 'Have seen' indicates that the researchers have observed something at some point in the past that is significant to their current discussion.

Wrong options:

• saw: 'Saw' is the simple past tense, which does not convey the ongoing relevance of the observation to the present.
• seen: 'Seen' is a past participle that requires an auxiliary verb to form a complete tense, making it incorrect on its own in this context.
• having seen: 'Having seen' is a perfect participle that does not fit the grammatical structure needed here.

Correct answer: scorching

Explanation: The word 'scorching' is an adjective that describes the extreme heat of the desert floor, fitting grammatically and contextually as it conveys the intensity of the environment the ants are navigating.

Meaning: 'Scorching' means extremely hot, indicating the harsh conditions of the desert floor that the ants must avoid.

Wrong options:

• emotional: 'Emotional' refers to feelings and does not relate to the physical condition of the desert floor.
• stuck: 'Stuck' implies being unable to move, which does not accurately describe the condition of the desert floor.
• unsensored: 'Unsensored' is not a standard English word and does not fit the context of describing temperature.

Correct answer: to benefit

Explanation: The phrase 'to benefit' is an infinitive form that indicates the potential for robotics to gain advantages from the discovery, fitting grammatically and contextually as it expresses purpose or intention.

Meaning: 'To benefit' means to gain an advantage or profit from something, indicating that robotics could improve due to the findings about ant locomotion.

Wrong options:

• benefited: 'Benefited' is the past tense form, which does not fit the future-oriented context of the sentence.
• benefit: 'Benefit' is a noun or present tense verb that does not fit the grammatical structure required here.
• benefits: 'Benefits' is a plural noun or present tense verb that does not align with the intended infinitive form.