A.I. Explanation:

Correct answer: competed

Explanation: The word 'competed' fits grammatically as it is the past participle form of the verb, aligning with the past tense context of the sentence. It indicates participation in a contest, which is appropriate here as it describes the supercomputer's engagement in a match against human gamers.

Meaning: 'Competed' means to take part in a contest or game, suggesting that the supercomputer was involved in a challenge against humans.

Wrong options:

• fought: 'Fought' implies a physical or aggressive confrontation, which does not accurately describe the nature of a video game match.
• challenged: 'Challenged' suggests initiating a contest rather than participating in one, making it less suitable in this context.
• acted: 'Acted' is too vague and does not convey the specific idea of engaging in a competition.

Correct answer: However

Explanation: 'However' serves as a contrasting conjunction, indicating a shift in thought from the previous statement about the computer's competition with humans. It fits well grammatically and contextually, as it introduces a contrasting idea about the computer's capabilities.

Meaning: 'However' means 'on the other hand' or 'nevertheless,' signaling a contrast to the previous statement about the computer's competition.

Wrong options:

• Moreover: 'Moreover' indicates an addition rather than a contrast, making it unsuitable for this context.
• Thus: 'Thus' implies a conclusion or result, which does not fit the contrasting nature of the following statement.
• So: 'So' suggests a consequence, which does not align with the intended contrast in the sentence.

Correct answer: set

Explanation: The word 'set' is the correct choice as it indicates that the programs are established or defined by humans. It fits grammatically as a past participle, aligning with the context of human control over the computer's functions.

Meaning: 'Set' means to establish or arrange something, indicating that the computer operates based on parameters defined by humans.

Wrong options:

• with: 'With' does not convey the idea of establishing or defining, making it grammatically and contextually inappropriate here.
• against: 'Against' implies opposition, which does not fit the context of programming or defining functions for the computer.
• about: 'About' is too vague and does not indicate the action of establishing programs.

Correct answer: yet

Explanation: The word 'yet' is used to indicate that something has not happened up to this point in time. It fits grammatically as an adverb modifying the verb 'developed,' and contextually it suggests that machine-learning has not reached a certain level of advancement.

Meaning: 'Yet' means 'up to now' or 'at this time,' indicating that machine-learning has not developed sufficiently to think independently.

Wrong options:

• still: 'Still' implies continuity, which does not convey the same sense of time as 'yet' in this context.
• only: 'Only' suggests limitation, which does not fit the context of development and advancement being discussed.
• just: 'Just' implies immediacy or simplicity, which does not accurately reflect the ongoing nature of development in machine-learning.