A cardiologist is a doctor who specializes in the study or treatment of heart diseases and heart abnormalities. A hematologist studies blood. A pulmonologist studies the respiratory system. A gastroenterologist studies the stomach and intestines.

An irascible person is having or showing a tendency to be easily angered. Testy means easily irritated. Choleric means bad-tempered or irritable. Petulant means childishly sulky or bad-tempered.

A testimonial is a formal written statement about a person's character and abilities. An affidavit is a written statement confirmed by oath for use as evidence in court. A manifesto is a public declaration of policy and aims. A memorandum is a written message in business or diplomacy.

A game or contest that ends without a winner is called a drawn game, or a draw. Decisive means settling an issue to produce a definitive result. Sanguinary means involving much bloodshed. An alternative is one of two or more available possibilities.

A deponent is a person who makes a deposition or affidavit under oath, which is written testimony. A witness gives testimony orally in court. An appellant appeals a decision. A litigant is a person involved in a lawsuit.

To 'strain every nerve' means to make the greatest possible effort to achieve something.

**Rule: Understanding Idiomatic Expressions.** The idiom 'on the ball' means to be quick to understand and react to things. Knowing the 'latest developments' shows that a person is attentive and competent. Option (b) is the correct definition. Option (a) and (d) are literal misinterpretations. Option (c) is the opposite.

**Rule: Understanding Idiomatic Expressions.** The idiom 'run riot' means to behave in a noisy, violent, and uncontrolled manner. This is a common way to describe children who are left unsupervised. Option (c) is the correct definition. Option (a) and (d) are the opposite of this behavior. Option (b) implies an organized protest, whereas 'run riot' implies chaos.

**Rule: Understanding Idiomatic Expressions.** The idiom 'up in arms' means to be very angry and protesting strongly about something. A plan to build a highway through a neighborhood is a common cause for community outrage. Option (c) correctly defines this reaction. Option (a) and (d) are literal misinterpretations. Option (b) is the opposite of the community's angry reaction.

**Rule: Understanding Idiomatic Expressions.** The idiom 'hold water' means that a statement, theory, or argument seems to be sound, logical, and able to stand up to scrutiny. Being 'consistent with all the evidence' is a key reason why the testimony would be considered valid. Option (c) is the correct definition. Option (a) is a literal interpretation. Option (b) is the opposite. Option (d) is irrelevant.