For time being， the most controversial but widely-used animal research， also known as animal experimentation or animal testing has arisen great public concern since a living organism is an important choice for the study of most diseases and health issues.
　　To many people， who oppose animal testing， it is cruel， inhumane and morally offensive to use animals in medical research， cosmetic testing， dissection and many other purposes. Moreover， animals are not completely consistent with human being that animal researches are likely unreliable. Others who approve may say that the animals are the most appropriate testing subjects for their biological similarities to the mankind. It is the researches based on experimental animals that have contributed a big advance in drug and medical science. In my opinion， animals testing should be used for scientific research.
　　Firstly， Humans and animals are almost identical in many ways. According to CBRA Fact Sheet： Why Are Animals Necessary in Biomedical Research？ （2013）， ‘Chimpanzees share 99% of their DNA with humans， and mice are 98% genetically similar to humans.’ As mentioned above， because of the similar body system， animals and humans could have the same health problems to a large extent， such as cancer， heart disease， diabetes and others （Wright， Kazdin，