１９９９年全国高考和１９９７年上海高考试题中的实验题都考了含双掷开关测量电阻的实物连接图，它们新颖灵活，都是考查学生实验操作技能的好题．其新颖之处，体现在单刀双掷开关、双刀双掷开关的出现．部分学生因平时对用双掷开关连接电路重视不够，考试时就普遍感到困难了 In 1999, both the national college entrance examination and the 1997 Shanghai high-examination questions in the experiment examined the physical connection diagram containing the resistance measurement of the double-throw switch. They are novel and flexible, and they are good questions for examining students’ experimental operation skills. Its novelty is reflected in the emergence of single pole double throw switch and double pole double throw switch. Some students usually do not pay enough attention to the use of a double-throw switch to connect the circuit. It is generally difficult to pass the test.