21 至 25 題為題組 A polygraph machine, also known as a “lie detector,” is a common part of criminal investigations. The instrument is used to measure _____21_____ a person’s body reacts to questions. The theory underlying it is that lying is stressful, and that this stress can be measured and recorded on a polygraph machine. When a person takes a polygraph test, four to six wires, called sensors, are _____22_____ to different parts of his body. The sensors pick up signals from the person’s blood pressure, pulse, and perspiration. _____23_____ the process of questioning, all the signals are recorded on a single strip of moving paper. Once the questions are finished, the examiner analyzes the results to determine if the person tested _____24_____ truthful. Well-trained examiners can usually detect lying with a high degree of _____25_____ when they use a polygraph. However, because different people behave differently when lying, a polygraph test is by no means perfect. 【題組】23.
(A) Before
(B) Among
(C) Without
(D) Throughout