初中生物第三册（河北版）第四章第四节《尿的形成》一课，教学重点是尿的形成过程，教学难点是肾小球的滤过作用和肾小管的重吸收作用。由于教材中的图示比较复杂、抽象，实验室仪器中又无现成教具辅助教学，加之初中生的抽象思维能力。空间想象力不够等，学生理解起来甚感吃 Junior middle school biology third volume (Hebei version) The fourth chapter “The formation of urine” lesson, teaching is the formation process of urine, teaching difficulties is the glomerular filtration and tubular reabsorption. Because the illustrations in the textbooks are more complex and abstract, there are no teaching aids for teaching aids in the laboratory instruments, plus the abstract thinking ability of junior high school students. Space imagination is not enough, students understand it very much