Secondly,teacher should introduce the cases,then instruct the students to find relative cases,and encourage them to take the advantage of returning home to practice defending and curing disease of fishes.

• 二是介绍病例,再指导学生在实际生产中去寻找有关病例,并鼓励学生利用暑假回家的机会在家乡进行鱼病防治实习。