**Rule: Understanding Idiomatic Expressions.** The idiom 'a house of cards' refers to a plan, structure, or argument that is unstable and can easily be destroyed. The fact that the case 'collapsed' when one piece of evidence was removed shows its inherent weakness. Option (c) is the correct definition. Option (a) is the literal object. Option (b) is the opposite. Option (d) is an unrelated interpretation.

**Rule: Understanding Idiomatic Expressions.** The idiom 'brass neck' refers to extreme boldness, audacity, or shamelessness (cheek). Asking for a raise after being caught for misconduct is a prime example of such behavior. Option (a) is the correct definition. Option (b) and (c) are literal misinterpretations. Option (d) is the opposite of having a brass neck.

**Rule: Understanding Idiomatic Expressions.** The idiom 'miss the boat' means to lose an opportunity by being too slow to act. By not applying for the job in time, the person lost the chance to be hired. Option (b) correctly defines this situation. Option (a) and (c) are literal interpretations. Option (d) is the opposite outcome.

**Rule: Understanding Idiomatic Expressions.** The idiom 'wet behind the ears' refers to someone who is immature and lacks experience, like a newborn animal that is still wet. The need for 'a lot of training' supports the idea of inexperience. Option (c) is the correct definition. Option (a) is a literal misinterpretation. Option (b) is the opposite. Option (d) is a different character flaw.

**Rule: Understanding Idiomatic Expressions.** The idiom 'sell like hot cakes' means to be sold very quickly and successfully. The fact that the tickets 'sold out in minutes' is a clear example of this. Option (b) is the correct definition. Option (a) is a literal interpretation. Option (c) is incorrect. Option (d) is the opposite of the idiom's meaning.

**Rule: Understanding Idiomatic Expressions.** The idiom 'go their separate ways' means to dissolve a relationship, partnership, or association. In the context of countries with 'political disputes', it signifies the end of their cooperation. Option (a) is the correct definition. Option (b) is a literal meaning but not the figurative one intended. Option (c) is the opposite. Option (d) is unrelated.

**Rule: Understanding Idiomatic Expressions.** The idiom 'keep a straight face' means to avoid laughing or showing amusement, even though one finds something funny. The fact that he 'burst out laughing' shows that he failed in his attempt to keep a straight face. Option (c) is the correct definition. Option (a) is a literal interpretation. Option (b) and (d) describe different expressions.

**Rule: Understanding Idiomatic Expressions.** The idiom 'to have a bee in one's bonnet' means to be obsessed with an idea or to be constantly thinking and talking about something, often to the point of annoyance for others. It implies a strong and persistent preoccupation. Option (b) is the correct definition. Option (a) is a literal and uncomfortable misinterpretation. Option (c) is the opposite. Option (d) is unrelated.

**Rule: Understanding Idiomatic Expressions.** The idiom 'take the bull by the horns' means to face a challenge or difficulty directly and decisively. Confronting one's boss is a difficult situation that requires courage. Option (b) correctly defines this approach. Option (a) and (d) are literal misinterpretations. Option (c) is the opposite of the idiom's meaning.

**Rule: Understanding Idiomatic Expressions.** The idiom 'just what the doctor ordered' refers to something that is precisely what is needed or desired to improve a situation. An 'inspiring speech' is exactly what a team with 'low morale' needs. Option (b) is the correct definition. Option (a) is the literal origin of the phrase. Option (c) is the opposite. Option (d) is a literal misinterpretation.