写作思路：说明研究动物的初衷和重要的原因，比如人类开展动物实验的初衷是为了了解和认识生命现象，怀疑和挑战宗教神学对人类思想的禁锢；人类研究动物的原因是在不能以人为实验对象的前提下，科学研究必须借助实验动物和动物实验，进行疾病机理和诊断治疗方法的研究，在安全、有效的情况下再推用到人类。
正文：
The original intention of animal experiment is to understand and understand the phenomenon of life, doubt and challenge the confinement of human thought by religious theology. This exploration and understanding has formed the basic life science theories of zoology, anatomy and physiology.
人类开展动物实验的初衷是为了了解和认识生命现象，怀疑和挑战宗教神学对人类思想的禁锢，这种探索和认识，形成了动物学、解剖学、生理学等基础生命科学理论。
When the understanding of normal anatomy and physiology of human and animals is gradually clear, the prevention and treatment of disease research began. Thanks to animal experiments, the theoretical system of modern medicine such as immunology, microbiology, infectious diseases and virology has been gradually formed.
当对人体和动物正常解剖与生理的认识逐步清楚后，才开始疾病的预防和治疗研究。得益于动物实验，逐步形成了免疫学、微生物学、传染病学、病毒学等现代医学的理论体系。
In the game between human and disease, cholera, smallpox, polio and other infectious diseases have taken a large number of innocent lives. Scientists have found that many human diseases occur in some animals as well.
人类与疾病的博弈中，霍乱、天花、脊髓灰质炎等传染病的暴发夺走了大量无辜的生命。科学家发现很多人类的疾病，在某些动物身上也会同样发生。
On the premise of not using human as experimental objects, scientific research must rely on experimental animals and animal experiments to study the disease mechanism, diagnosis and treatment methods, and then apply it to human beings under safe and effective conditions.
在不能以人为实验对象的前提下，科学研究必须借助实验动物和动物实验，进行疾病机理和诊断治疗方法的研究，在安全、有效的情况下再推用到人类。