自考英语二考试重点：unit 11 常考句型
the use of animals has been central to the development of anaesthetics.
animal research is irrelevant to our health and it can often produce misleading results.
people and animals are different in their reactions to drugs and in the way their bodies work.
it would be completely irresponsible and unethical to use drugs on people that had not been thoroughly tested on animals.