**Rule: Understanding Idiomatic Expressions.** The idiom 'a law unto himself' describes a person who acts as if they are not bound by the normal rules or standards of behaviour that govern others. The fact that the boss 'doesn't follow the company's rules' is a direct explanation of this idiom. Option (b) is the correct definition. Option (a) and (d) are related to law but are not the meaning of the idiom. Option (c) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'the short end of the stick' refers to getting the unfair or disadvantageous share of something. Having to do a job alone that should be shared is a clear example of an unfair outcome. Option (c) is the correct definition. Option (a) and (d) are the opposite. Option (b) is a literal misinterpretation.

**Rule: Understanding Idiomatic Expressions.** The idiom 'all ears' means to be fully focused and keen to listen to what someone is about to say. One would expect students to listen attentively to a 'famous author'. Option (c) is the correct definition. Option (b) is a literal misinterpretation. Options (a) and (d) are the opposite of attentive listening.

**Rule: Understanding Idiomatic Expressions.** The idiom 'off the beaten track' (or 'path') refers to something that is uncommon, unconventional, or in a remote location. When applied to ideas, it means they are original and not mainstream. The word 'revolutionary' supports this meaning. Option (b) is the correct definition. Option (a) is the opposite. Option (c) is a literal interpretation. Option (d) is a different negative quality.

**Rule: Understanding Idiomatic Expressions.** The idiom 'feel it in one's water' is a British expression meaning to have a premonition or a gut feeling about something, without having any concrete evidence. It is similar to 'feel it in one's bones'. Option (a) is the correct definition. Option (b) and (d) are literal misinterpretations. Option (c) is the opposite of having a strong feeling.

**Rule: Understanding Idiomatic Expressions.** The idiom 'pour oil on troubled waters' means to say or do something to pacify a quarrel or calm a tense situation. It originates from the ancient practice of pouring oil on the sea to calm the waves. A 'heated debate' is a situation that needs calming. Option (b) is the correct definition. Option (a) describes 'adding fuel to the fire'. Option (c) is a literal interpretation. Option (d) is a different approach.

**Rule: Understanding Idiomatic Expressions.** A 'fair-weather friend' is someone who is only friendly and supportive when it is easy or convenient for them. The phrase 'never around when I have problems' is a direct explanation of this type of unreliable friend. Option (a) is the correct definition. Option (c) is the opposite. Options (b) and (d) are literal misinterpretations.

**Rule: Understanding Idiomatic Expressions.** The idiom 'a castle in the air' (or 'castles in the sky') refers to an extravagant plan or hope that is impractical and has no solid foundation. The lack of 'realistic funding or timeline' confirms the impracticality of the project. Option (b) is the correct definition. Option (a) is the opposite. Option (c) and (d) are literal misinterpretations.

**Rule: Understanding Idiomatic Expressions.** The word 'cheek' is used idiomatically to mean audacity, impudence, or behaviour that is bold in a rude way. Asking for more money without repaying a previous debt is a classic example of cheeky behaviour. Option (c) is the correct definition. Option (a) is the literal meaning. Options (b) and (d) are the opposite of having cheek.

**Rule: Understanding Idiomatic Expressions.** The idiom 'in the black' means to be financially profitable. It comes from the accounting practice of using black ink to indicate profits, as opposed to red ink for losses. Option (b) is the correct definition. Option (a) describes being 'in the red'. Option (c) is an incorrect interpretation. Option (d) is a literal misinterpretation.