There are contentious heated debates over whether doing experiments on animals for medical purposes is tolerable or not. Before forming any opinions, it is necessary to discuss both perceptions, and I will delve into both approaches in the 
next
 paragraphs.
Advocates for animals medical Linking Words
research
 claim that humans can permit ourselves to conduct experiments on other species because they believe in natural selection. In reality, the law of evolution will eliminate the weak, and the strong will survive. If we allow ourselves to use other animals for Use synonyms
research
 to find ways to cure serious illnesses, we can avoid the extinct of humankind. Use synonyms
For example
, to produce the vaccine for the H5N1 virus, many rats or birds died in laboratory experiments; Linking Words
however
, humans found a way to stop a disease which could have led to the edge of human extinction.
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On the other hand
, animals medical Linking Words
research
 Use synonyms
also
 arouse a great deal of controversy since the opponents state that Linking Words
this
 activity is immoral. From the humanitarian perspective, scientists have no moral right to cause any discomfort or pain on animals, yet it is necessary to do Linking Words
this
 as a way to protect our species. If the ultimate goal is for serious medical purposes, Linking Words
then
 scientists can experiment on animals. Linking Words
Nevertheless
, if experimentation is only for beauty produces, the practice must be banned entirely.  
In conclusion, using animals for medical Linking Words
research
 can be justified on a moral basis and under strict conditions. In my opinion, the boundary between what is moral and immoral in using animals for medical Use synonyms
research
 is thin, and it is our responsibilities to draw the line and raise red flat towards unnecessary experiments. Not until there is an emergency which causes severe threats to humanity, Use synonyms
then
 we can use animals experiences as the Linking Words
last
 option.Linking Words