**Rule: Understanding Idiomatic Expressions.** The idiom 'skating on thin ice' means to be in a precarious or dangerous situation. Submitting a report late to a boss is a risky action that could lead to negative consequences. Option (b) correctly defines this risk. Option (a) is a literal interpretation. Option (c) and (d) are the opposite of the idiom's meaning.

**Rule: Understanding Idiomatic Expressions.** The idiom 'a flash in the pan' refers to something that has a sudden, brilliant, but short-lived success and is not repeated. The context of being 'hugely popular for a month and then disappeared' perfectly illustrates this meaning. Option (a) is the correct definition. Option (b) is the opposite. Option (c) is a literal misinterpretation. Option (d) is incorrect as the idiom implies a brief period of success before failure.

**Rule: Understanding Idiomatic Expressions.** The idiom 'have a lot on one's plate' means to be very busy with a large number of responsibilities or problems. A 'new job' and a 'new baby' are two major life events that would create a lot of tasks and stress. Option (c) is the correct definition. Option (a) is a literal misinterpretation. Option (b) is the opposite. Option (d) is an unrelated profession.

**Rule: Understanding Idiomatic Expressions.** The idiom 'up in the air' describes a plan or issue that has not yet been settled or decided. An election that is 'too close to call' is a perfect example of an uncertain outcome. Option (c) is the correct definition. Option (a) is a literal misinterpretation. Option (b) is the opposite. Option (d) is a possible but unrelated fact.

**Rule: Understanding Idiomatic Expressions.** The idiom 'pull out all the stops' means to use all the resources and effort available to achieve something. It originates from the 'stops' on a pipe organ, which are pulled out to turn on all the sounds. Option (b) is the correct definition. Option (a) is the literal origin. Options (c) and (d) are the opposite of making a maximum effort.

**Rule: Understanding Idiomatic Expressions.** The idiom 'at heart' is used to talk about what someone is really like, despite their outward appearance or behavior. It refers to one's fundamental character. Option (a) is the correct definition. Option (b) and (d) are literal misinterpretations. Option (c) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'the green-eyed monster' is a metaphor for jealousy. The phrase was coined by Shakespeare in his play Othello. Someone getting a promotion is a common trigger for envy in others. Option (b) is the correct definition. Option (a) is the opposite. Option (c) is a literal interpretation. Option (d) is a different emotion.

**Rule: Understanding Idiomatic Expressions.** The idiom 'full of holes' is used to describe an argument, plan, or story that is weak and has many faults, making it easy to criticize or disprove. The fact that the 'jury didn't believe it' shows its lack of credibility. Option (a) is the correct definition. Option (b) and (d) are literal misinterpretations. Option (c) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The informal idiom 'a big cheese' refers to an important or powerful person in a group or organization. The sentence implies that he has an inflated sense of his own importance. Option (b) is the correct definition. Option (a) and (d) are literal misinterpretations. Option (c) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'the spitting image of' (or 'spit and image') means to have an exact likeness or resemblance to someone else, particularly a relative. Option (b) is the correct definition. Option (a) is a literal misinterpretation. Option (c) is the opposite. Option (d) is a type of image, but not the meaning of the idiom.