Similarly , rearing goldfish can inspire people to find the answers to questions like what species of fish they are and how they breed ? are they oviparous 同样，饲养金鱼令人对金鱼的一切产生兴趣，如品种类别、培殖方法、卵生与否、鱼缸环境、疾病控制和饲养须知等等。
3.
As object lessons to explain : 1 the nature and habits of oviparous animals , the possibility of aerial flight , certain abnormalities of vision , the secular process of imbalsamation : 2 the principle of the pendulum , exemplified in bob , wheelgear and regulator , the translation in terms of human or social regulation of the various positions clockwise of movable indicators on an unmoving dial , the exactitude of the recurrence per hour of an instant in each hour , when the longer and the shorter indicator were at the same angle of inclination , videlicet , 5 5 11 minutes past each hour per hour in arithmetical progression 他把它们作为实物教材，用以说明： 1卵生动物的本性与习性，空中飞行的可能性，一种异常的视觉器官，世俗界用防腐药物保存尸体的方式。 2体现于摆锤轮与整时器上的钟摆的原理不动的针盘上那可移动的正转的长短指针在各个位置作为人或社会规范所包含的意义长针和短针每小时在同一倾斜度相遇的那一瞬间，也就是说，按照算术级数，每小时超过5 5 11分的那一瞬间，每小时重复一次的精确性146 。
