在近几年的高考试题中,经常出现这样一类选择题:“……下面给出的四个表达式中只有一个是合理的,你可能不会求解,但是你可以通过一定的物理分析,对下列表达式的合理性做出判断。根据你的判断,其合理的表达式应为”。由于题目所涉及的物理情境并不在高中物理课本的范围之内,因此很多考生由于知识缺陷,往往对此束手无策。 In recent college entrance examination exams, such a type of multiple choice question often appears: “... Only one of the four expressions given below is reasonable and you may not be able to solve it, but you can pass some physical analysis , To judge the rationality of the following expressions, according to your judgment, its reasonable expression should be ”. Because the subject involved in the physical situation is not within the scope of high school physics textbooks, many candidates because of knowledge deficits, often helpless.