对第二届全国奥赛(初三组)试题谈一些粗略的看法。通观全篇,这套奥赛题文字叙述精炼而清楚,条件充分必要,所做答案要求学生逻辑推理严密,必须熟练掌握课本的概念、公式、定律并善思多辨。如:例1:(奥赛第6题)如图1,两根水平放置的光滑金属导轨 MN 和 M′N′放置在均匀的磁场内,磁场方向垂直图面指向里,AB、CD是可在导轨上滑动的金属棒。当 AB 在外力作用下向右运动 Discussed some rough opinions on the second national Olympics (third grade) test questions. Throughout the entire chapter, this set of Olympiad title narratives are concise and clear, and the conditions are adequate and necessary. The answers to the questions require that students have strict logical reasoning, and must be proficient in the concept, formula, and law of the textbooks and be good at discriminating. For example: Example 1: (Orsay Question 6) As shown in Figure 1, two horizontally placed smooth metal rails MN and M’N’ are placed in a uniform magnetic field, and the vertical direction of the magnetic field points inwards. AB and CD are available at Slide metal bars on the rails. When AB moves to the right under external force