Beginning：
Many years – conservationists and animal rights groups- arguing that –animal experiments are not cruel – I agree/disagree – following reasons:
Body：
Reason1---agree:
topic sentence: Animal experiments are justified to relieve human suffering论述：the reduction of human suffering is our first priority and the prevention of animal suffering or death is secondary to that (although still important). So that if there is a decent（following moral standards that are acceptable to society） chance that an experiment will result in an important medical breakthrough that will reduce human suffering and death then it is justifiable to allow animal suffering. Animal experimentation is the (sometimes distasteful（unpleasant or morally offensive）) means to much greater ends.
Digress:
topic sentence: Animal experiments are cruel because of the animals’ suffering
Animals have the right to be treated as beings of value in themselves, not as the means to human ends; To infect monkeys with the AIDS virus or to expose rodents（啮齿动物） to toxic chemicals and radiation（[辐射） is simply not acceptable, whatever the supposed benefits.
Reason2—agree
topic sentence: to prevent animal suffering, in practice it is possible (and absolutely right) to keep animal suffering to an absolute minimum.
Animal experimenters should aspire to the highest levels of animal welfare in their laboratories, using anaesthetics（麻醉学） wherever possible and keeping animals in clean, comfortable, and healthy conditions. In short（＝to sum up/to summarize/in summary）, it is possible to experiment on animals without being cruel to animals.
disagree：
topic sentence: In practice, as everyone knows, animals are not routinely（if something is routinely done, it is done as a normal part of a process or job例行公事地） treated well by animal experimenters.