**Rule: Understanding Idiomatic Expressions.** The idiom 'keep one's head' means to stay calm and rational during a time of crisis or difficulty. Not 'panic-selling' during a 'market crash' is a clear example of remaining calm. Option (a) correctly defines this action. Options (b) and (d) describe negative reactions, the opposite of the idiom. Option (c) is a literal misinterpretation.

**Rule: Understanding Idiomatic Expressions.** The idiom 'all at sea' means to be in a state of confusion or to be lost and unsure of what to do. The context of a new intern needing a mentor for 'new software' supports this meaning of confusion. Option (c) is the correct definition. Option (b) is a literal misinterpretation. Options (a) and (d) are the opposite of being confused.

**Rule: Understanding Idiomatic Expressions.** The idiom 'a pillar of strength' refers to a person who is a source of great support and comfort to others in times of trouble. The word 'pillar' is used metaphorically to suggest someone who is strong and holds things up. Option (c) is the correct definition. Option (a) is the literal meaning of 'pillar.' Option (b) and (d) are the opposite of the idiom's meaning.

**Rule: Understanding Idiomatic Expressions.** The idiom 'draw a blank' means to fail to find something one is looking for or to be unable to remember something. In a police investigation, it means failing to find any leads or evidence. Option (a) is the correct definition. Option (b) is a literal misinterpretation. Option (c) is the opposite. Option (d) is a different meaning of 'blank'.

**Rule: Understanding Idiomatic Expressions.** The idiom 'bad blood' refers to feelings of ill will, resentment, or hostility between people. An 'argument' is a common cause of such feelings. Option (c) is the correct definition. Option (a) and (d) are literal misinterpretations. Option (b) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'against the clock' means to be rushed and have a very limited amount of time to complete something. A 'deadline' imposes a time limit, forcing one to work quickly. Option (a) is the correct definition. Option (b) is a literal misinterpretation. Option (c) is the opposite. Option (d) describes when one might work, but not the pace.

**Rule: Understanding Idiomatic Expressions.** The idiom 'the cat's whiskers' (or 'the cat's pyjamas') refers to someone or something that is considered excellent or superior. If a person thinks they are the cat's whiskers, they have a very high opinion of themselves. Option (a) correctly explains this feeling of superiority. Option (b) and (d) are literal misinterpretations. Option (c) is the opposite feeling.

**Rule: Understanding Idiomatic Expressions.** The idiom 'get up on the wrong side of the bed' means to start the day in a bad mood, which then continues for some time. Being 'grumpy all morning' is a direct result of this. Option (b) is the correct definition. Option (a) is the literal interpretation, but the idiom is figurative. Option (c) is unrelated. Option (d) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'add fuel to the fire' (or 'flames') means to do or say something that makes an already bad situation, argument, or feeling even more intense. A controversial statement would worsen a heated 'political debate.' 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 'cut corners' means to take shortcuts and do something in a less thorough way than is standard, usually to save time or money. This often results in a lower quality product or service, which is why doctors would be worried about a healthcare bill. Option (a) is the correct definition. Option (b) is a literal misinterpretation. Options (c) and (d) are the opposite of cutting corners.