Experiments on monkeys were viewed much more negatively than those involving mouse. Indeed, only experiments to develop【M1】______ drugs to treat childhood leukemia were seen as justifying monkeys suffering. In Britain, experiments involving primates are very tightly controlled. Researchers must convince government officials that the knowledge be gained justifies any suffering to the animals, and that【M2】______ adequate data cannot be obtained by using other species. In practice, this means what monkeys are unlikely to be used in【M3】______ leukemia research, as the disease can be studied in other animals. So【M4】______ attempts to develop AIDS vaccines depend heavily on experiments of related viruses in monkeys, in which some of the animals are likely【M5】______ to become ill. Our poll indicates that a majority of British people would oppose these experiments. In the US, where regulations are less stringent, the goal of developing an AIDS vaccine is seen as sufficient justification for injecting chimpanzees potentially lethal strains of HIV. And while【M6】______ most people are probably not aware of such facts, 64 percent of those we polled judged correctly that regulations governing animal experiments in Britain are stricter than these in other developed【M7】______ countries. Just 11 percent thought that British rules are less strict, while 24 percent said they didnt know. On one respect, however, our poll reveals a disturbing gap in【M8】______ peoples knowledge which the British government might want to address. No prescription drug is marked without at first being tested【M9】______ in animals, yet people are either unaware that this is the case, but【M10】______ dont want to acknowledge the fact. 【M1】