The transplantation of functioning human immune systems into mice was reported by two California research teams in September 1988.The mice should have many important uses in medical science,such as enabling researchers to test treatments against a number of diseases and to study the effects of infectious microorganisms-including the AIDS virus-on the human immune system. 
　　Both research groups-at the Medical Biology Institute in La Jolla and at Standford University-started with a special strain of mice that are without an immune system.The La Jolla scientists injected the mice with human B cells and T cells,white blood cells that are major components of the immune system.The cells reproduced in the mice’s bodies and migrated throughout the animals’circulatory systems. 
　　The Stanford researchers implanted human fetal lival tissues,thymus�瞘land tissues,and lymph nodes,into the mice.In the mice’ bodies,the liver cells produced stem cells,which develop into the various kinds of blood cells.The implanted tissues converted the stem cells into B cells and T cells. 
　　The mice with immune�瞫ystem transplants by both research teams were fully protected against infectious disease.Ordinarily,mice of the strain used by the scientists die soon after birth unless they are kept in a sterile(無菌的)environment. 
　　The purpose of the researches in those two universities was to _____ ． 
　　A．use mouse blood to treat many diseases 
　　B．use human blood to cure sick mice 
　　C．find out how human immune system might be affected 
　　D．find out if human immune system was similar to that of mice 
　　The two researchers were similar in that both research groups _____ ． 
　　A．had the same objective to their researches 
　　B．used the same procedures in their researches 
　　C．injected the same kind of blood cells into the mice 
　　D．used the same experimental instrument in their work 
　　Finally the two researches _____ ． 
　　A．had quite different findings 
　　B．got similar findings 
　　C．failed since the mice soon died 
　　D．had no particular results  
　　Comparedwith Standford University researchers,those in the other university _____ ．  
　　A．experimented with fewer kinds of blood cells 
　　B．used a less advanced method 
　　C．employed a more direct method 
　　D．got less convincing results