Rule: Rhetorical Devices. A fire station burning down is a classic example of situational irony, where the outcome is incongruous with what one would expect. The very place designed to fight fires succumbs to fire. While it is also a 'tragedy' (a), 'irony' (c) specifically captures the strange and contradictory nature of the event. 'Comedy' (b) is unlikely as it's a serious event. 'Predictability' (d) is the exact opposite of what makes the situation notable.

Rule: Vocabulary of Labor Relations. Paying workers less than the legal minimum wage is an act of taking unfair advantage of them. 'Exploiting' means to make full use of and derive benefit from (a resource), often unfairly. This is the correct term for the company's illegal and unfair action. Options (a) 'rewarding', (b) 'compensating', and (d) 'praising' are all positive actions.

Rule: Vocabulary of Foretelling. A prophecy is something that foretells the future. A 'harbinger' is a person or thing that announces or signals the approach of another. It is a synonym for a sign or omen, which fits the context of a prophecy foretelling a war. Options (b) 'consequence' and (c) 'result' would come after the war. Option (d) 'memory' would also come after.

Rule: Vocabulary of Personality. A career in nursing requires a selfless concern for others. 'Altruistic' means showing a disinterested and selfless concern for the well-being of others; unselfish. This word perfectly describes the ideal nature for a nurse. Options (a) 'callous' (unfeeling), (b) 'malevolent' (wishing to do evil), and (d) 'selfish' are all antonyms.

Rule: Political/Economic Vocabulary. A government order to stop trade with another country, especially for political reasons, is called an embargo. 'Embargo' is an official ban on trade or other commercial activity with a particular country. This is the correct term. Options (a) 'incentive', (c) 'allowance', and (d) 'subsidy' are all forms of financial help or encouragement, not restrictions.

Rule: Vocabulary of Argumentation. The sentence is describing the general meaning or gist of the argument. 'Tenor' means the general meaning, sense, or content of something. It is the perfect word to describe the overall thrust of his argument. Options (a) 'digression', (c) 'distraction', and (d) 'ornamentation' (unnecessary details) are all peripheral to the main point.

Rule: Vocabulary of Lifestyles. A person who 'shuns society' and lives a 'solitary life' is a recluse. 'Recluse' is a person who lives a solitary life and tends to avoid other people. This word perfectly fits the description. Options (a) 'socialite', (b) 'extrovert', and (d) 'celebrity' are all people who are typically very involved with society.

Rule: Geographical Vocabulary. A fertile delta is formed where rivers meet and deposit sediment. 'Confluence' is the junction of two rivers, especially rivers of approximately equal width. This is the precise geographical term. Options (a) 'divergence', (b) 'separation', and (d) 'bifurcation' (division into two branches) are all words for rivers splitting apart, not joining.

Rule: Vocabulary of Deception. Promises that one has 'no intention of keeping' are misleading and false, even if they sound good. 'Specious' means superficially plausible, but actually wrong. It perfectly describes promises that sound attractive but are ultimately baseless. Options (a) 'sincere', (b) 'concrete', and (d) 'binding' are all words for real, genuine promises.

Rule: Logical Inference. For ruins to be 'revealed', the thing covering them must have been removed or pulled back. 'Receding' means to go or move back or further away from a previous position. The receding of the rainforest (due to deforestation or climate change) would logically reveal what was underneath. Option (a) 'canopy' is a part of the forest. Options (c) 'growth' and (d) 'expansion' would hide the ruins, not reveal them.