Is a mouse that can speak acceptable? How about a dog with human hands or feet? Scientists, the people with the know-how to make such things happen, are now thinking about whether such experiments are morally right or not.     On Nov. 10, Britain's Academy of Medical Sciences launched a study on the use of animals with human materials in scientific research. The work is expected to take at least a year, but its leaders hope it will lead to guidelines for scientists in Britain and around the world on how far  _ can go mixing human genes into animals in search of ways to fight human diseases. "Do these constructs   challenge our idea of what it is to be human?" asked Martin Bobrow, a professor of medical genetics at Cambridge University and chair of a 14-member group looking into the issue. "It is important that we consider these questions now so that appropriate boundaries are recognized."       Using human material in animals is not new. Scientists have already created monkeys that have a human form of the Huntingdon's gene so they can study how the disease develops; and mice with livers   made from human cells are being used to study the effects of new drugs. However, scientists say the technology to put ever greater amounts of human genetic material into animals is spreading quickly around the world --- raising the possibility that some scientists in some places may want to go further than is morally acceptable.      Last year in Britain there was a lively debate over new laws allowing the creation of human-animal embryos   for experiments. On one side of the debate were religious groups, who claimed that such science interferes with nature. Opposing them were scientists who pointed out that such experiments were vital to research cures for diseases.  The experts will publish reports after the end of the study, in which they will give definitions   for animal embryos with human genes or cells, look at safety and animal welfare issues, and consider the right legal framework to work within. We can infer from the passage that   _  .
the experts will release reports after the study scientists have never doubted the use of animals with human materials the creation of human-animal embryos for experiments is legal in Britain religious groups hold that cures for diseases have to be done through experiments