**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.

**Rule: Understanding Idiomatic Expressions.** The idiom 'open a can of worms' means to take an action that inadvertently leads to a host of new, unforeseen troubles. The fact that the policy 'creating more problems than it solved' is a clear example of this. Option (b) is the correct definition. Option (a) is a literal interpretation. Option (c) and (d) are the opposite of the idiom's meaning.

**Rule: Understanding Idiomatic Expressions.** The term 'vested interest' refers to a strong personal reason for wanting something to happen because one will benefit from it. Owning stock in a company gives a person a direct financial reason to want the company to succeed. Option (a) is the correct definition. Option (b) is a literal misinterpretation of 'vest'. Option (c) is the opposite of a personal interest. Option (d) is the opposite of having a strong interest.